Methods, access point and wireless transmit/receive unit to generate a basic service set
27 claims: 4 independent, 23 dependent
- 1Zastrzeżenia patentowe 1. Sposób dla punktu dostępowego AP, obejmujący:generowanie elementu obciążenia podstawowego zestawu usług, BSS, zawierającego wiele usługowych elementów obciążenia usługi z kategorii dostępu, AC, po jednym dla każdej kategorii dostępu: kategorii AC głosu, kategorii AC wideo, kategorii AC niegwarantowanego dostarczenia, oraz kategorii AC tła, przy czym każdy z wielu elementów obciążenia usługi z kategorii AC wskazuje odpowiednią kategorię dostępu AC oraz jeden z następujących elementów: skalowaną reprezentację średniego opóźnienia dostępu dla wskazanej kategorii dostępu AC;że usługa dla wskazanej kategorii dostępu AC jest obecnie niedostępna;lub że średnie opóźnienie dostępu dla wskazanej kategorii dostępu AC nie jest dostępne;a także transmitowanie elementu obciążenia zestawu BSS do wielu bezprzewodowych jednostek nadawczo/odbiorczych WTRU.
- 2Sposób według zastrzeżenia 1, w którym średnie opóźnienie dostępu jest mierzone podczas z góry określonego okresu czasu.
- 3Sposób według zastrzeżenia 2, w którym okres czasu wynosi trzydzieści, 30, sekund. 53/59P30829PL00
- 4Sposób według zastrzeżenia 1, w którym element obciążenia zestawu BSS zawiera 4 oktety, zaś każda z kategorii dostępu:kategoria AC niegwarantowanego dostarczenia, kategoria AC tła, kategoria AC głosu oraz kategoria AC wideo, stanowi inny oktet spośród tych 4 oktetów.
- 5Sposób według zastrzeżenia 1, w którym wartość mniejsza niż 253 w jednym z elementów obciążenia usługi z kategorii AC wskazuje skalowaną reprezentację średniego opóźnienia dostępu dla wskazanej kategorii dostępu AC.
- 6Sposób według zastrzeżenia 1, w którym wartość 253 w jednym z elementów obciążenia usługi z kategorii AC wskazuje na opóźnienie większe niż wartość progowa.
- 7Sposób według zastrzeżenia 1, w którym wartość 254 w jednym z elementów obciążenia usługi z kategorii AC wskazuje, że usługa dla wskazywanej kategorii dostępu AC jest obecnie niedostępna.
- 8Sposób według zastrzeżenia 1, w którym wartość 255 w jednym z elementów obciążenia usługi z kategorii AC wskazuje, że średnie opóźnienie dostępu dla wskazanej kategorii dostępu AC nie jest dostępne.
- 9Punkt dostępowy AP, zawierający:procesor skonfigurowany do generowania elementu obciążenia podstawowego zestawu usług, BSS, zawierającego wiele elementów obciążenia usługi z kategorii dostępu, AC, po jednym dla każdej kategorii dostępu: kategorii AC głosu, kategorii AC wideo, kategorii AC niegwarantowanego dostarczenia i kategorii AC tła, przy czym każdy wielu z elementów obciążenia usługi z kategorii AC wskazuje odpowiednią kategorię dostępu AC oraz jeden z następujących elementów: 53/59P30829PL00 skalowaną reprezentację średniego opóźnienia dostępu dla wskazanej kategorii dostępu AC;że usługa dla wskazanej kategorii dostępu AC jest obecnie niedostępna;lub że średnie opóźnienie dostępu dla wskazanej kategorii dostępu AC nie jest dostępne;a także nadajnik skonfigurowany do transmitowania elementu obciążenia zestawu BSS do wielu bezprzewodowych jednostek nadawczo/odbiorczych, WTRU.
- 10Punkt AP według zastrzeżenia 9, w którym:odbiornik jest skonfigurowany do odbierania elementu obciążenia zestawu BSS od innego punktu AP.
- 11Punkt AP według zastrzeżenia 9, w którym średnie opóźnienie dostępu jest mierzone podczas z góry określonego okresu czasu.
- 12Punkt AP według zastrzeżenia 11, w którym okres czasu wynosi trzydzieści, 30, sekund.
- 13Punkt AP według zastrzeżenia 9, w którym element obciążenia zestawu BSS zawiera 4 oktety, zaś każda z kategorii dostępu:kategoria AC niegwarantowanego dostarczenia, kategoria AC tła, kategoria AC głosu oraz kategoria AC wideo, stanowi inny oktet spośród tych 4 oktetów.
- 14Punkt AP według zastrzeżenia 9, w którym wartość mniejsza niż 253 w jednym z elementów obciążenia usługi z kategorii AC wskazuje skalowaną reprezentację średniego opóźnienia dostępu dla wskazywanej kategorii dostępu AC. 53/59P30829PL00
- 15Punkt AP według zastrzeżenia 9, w którym wartość 253 w jednym z elementów obciążenia usługi z kategorii AC wskazuje na opóźnienie większe niż wartość progowa.
- 16Punkt AP według zastrzeżenia 9, w którym wartość 254 w jednym z elementów obciążenia usługi z kategorii AC wskazuje, że usługa dla wskazywanej kategorii dostępu AC jest obecnie niedostępna.
- 17Punkt AP według zastrzeżenia 9, w którym wartość 255 w jednym z elementów obciążenia usługi z kategorii AC wskazuje, że średnie opóźnienie dostępu dla wskazywanej kategorii dostępu AC nie jest dostępne.
- 18Bezprzewodowa jednostka nadawczo/odbiorcza WTRU zawieraj ąca:odbiornik skonfigurowany do odbioru elementu obciążenia podstawowego zestawu usługowego, BSS, zawierającego wiele elementów obciążenia usługi z kategorii dostępu AC, po jednym dla każdej kategorii dostępu: kategorii AC głosu, kategorii AC wideo, kategorii AC niegwarantowanego dostarczenia oraz kategorii AC tła, przy czym każdy z wielu elementów obciążenia usługi z kategorii AC wskazuje na odpowiednią kategorię dostępu AC oraz jeden z następujących elementów: skalowaną reprezentację średniego opóźnienia dostępu dla wskazanej kategorii dostępu AC;że usługa dla wskazanej kategorii dostępu AC jest obecnie niedostępna;lub że średnie opóźnienie dostępu dla wskazanej kategorii dostępu AC nie jest dostępne.
- 19Jednostka WTRU według zastrzeżenia 18, w której wartość mniejsza niż 253 w jednym z elementów obciążenia usługi z 53/59P30829PL00 kategorii AC wskazuje skalowaną reprezentację średniego opóźnienia dostępu dla wskazywanej kategorii dostępu AC.
- 20Jednostka WTRU według zastrzeżenia 18, w której wartość 253 w jednym z elementów obciążenia usługi z kategorii AC wskazuje na opóźnienie większe niż wartość progowa.
- 21Jednostka WTRU według zastrzeżenia 18, w której wartość 254 w jednym z elementów obciążenia usługi z kategorii AC wskazuje, że usługa dla wskazywanej kategorii dostępu AC jest obecnie niedostępna.
- 22Jednostka WTRU według zastrzeżenia 18, w której wartość 255 w jednym z elementów obciążenia usługi z kategorii AC wskazuje, że średnie opóźnienie dostępu dla wskazywanej kategorii dostępu AC nie jest dostępne.
- 23Sposób dla bezprzewodowej jednostki nadawczo/odbiorczej WTRU, który to sposób obejmuje:odbierania elementu obciążenia podstawowego zestawu usług, BSS, zawierającego wiele elementów obciążenia usługi z kategorii dostępu, AC, po jednym dla każdej kategorii dostępu: kategorii AC głosu, kategorii AC wideo, kategorii AC niegwarantowanego dostarczenia i kategorii AC tła, przy czym każdy wielu z elementów obciążenia usługi z kategorii AC wskazuje odpowiednią kategorię dostępu AC oraz jeden z następujących elementów: skalowaną reprezentację średniego opóźnienia dostępu dla wskazanej kategorii dostępu AC;że usługa dla wskazanej kategorii dostępu AC jest obecnie niedostępna;lub że średnie opóźnienie dostępu dla wskazanej kategorii dostępu AC nie jest dostępne;53/59P30829PL00
- 24Sposób według zastrzeżenia 23, w którym wartość mniejsza niż 253 w jednym z elementów obciążenia usługi z kategorii AC wskazuje skalowaną reprezentację średniego opóźnienia dostępu dla wskazywanej kategorii dostępu AC.
- 25Sposób według zastrzeżenia 23, w którym wartość 253 w jednym z elementów obciążenia usługi z kategorii AC wskazuje na opóźnienie większe niż wartość progowa.
- 26Sposób według zastrzeżenia 23, w którym której wartość 254 w jednym z elementów obciążenia usługi z kategorii AC wskazuje, że usługa dla wskazywanej kategorii dostępu AC jest obecnie niedostępna.
- 27Sposób według zastrzeżenia 23, w którym wartość 255 w jednym z elementów obciążenia usługi z kategorii AC wskazuje, że średnie opóźnienie dostępu dla wskazywanej kategorii dostępu AC nie jest dostępne. INTERDIGITAL TECHNLOGY CORPORATION Pełnomocnik:53/59P30829PL00 53/59Ρ30829PL00 WĘZEŁ BSS 53/59P30829PL00 POWRÓT POWRÓT POWRÓT FIG. 3 53/59P30829PL00 AP FIG. 4 53/59P30829PL00 WTRU S252s INIJALIZUJ LICZNIK TSQ ZEREM S32> WTRU INIJALIZUJ LICZNIK CTQSZEREM WTRU S39> INIJALIZUJ LICZNIK CFTSQ ZEREM S26^ : ODBIERZ RAMKĘ ODBIERZ RAMKĘ RYWALIZACJI S40^ · ODBIERZ RAMKĘ BEZ RYWALIZACJI S27 KOLEJKUJ RAMKĘ W WARSTWIE MAC S34 KOLEJKUJ RAMKĘ W “ WARSTWIE MAC KOLEJKUJ RAMKĘ W WARSTWIE MAC S28 ZWIĘKSZ LICZNIK TSQ O LICZBĘ BAJTÓW W KOLEJKOWANEJ RAMCE _________Mr ZWIĘKSZ LICZNIK CTQS O LICZBĘ BAJTÓW W KOLEJKOWANEJ RAMCE S42 __________Mr ZWIĘKSZ LICZNIK CFTOS O LICZBĘ BAJTÓW W KOLEJKOWANEJ RAMCE S29 TRANSMITUJ RAMKĘ Z WYKORZYSTANIEM WARSTWY PHY S30 S36·^ ;________ TRANSMITUJ RAMKĘ RYWALIZACJI Z WYKORZYSTANIEM WARSTWY PHY S37 S43-^ : TRANSMITUJ RAMKĘ BEZ RYWALIZACJI Z WYKORZYSTANIEM WARSTWY PHY S44T I ZMNIEJSZ LICZNIK TOS O LICZBĘ BAJTÓW TRANSMITOWANYCH ALBO W TRYBIE BEZ POTWIERDZENIA ALBO KIEDY RAMKA JEST POTWIERDZONA PO TRANSMISJI WARSTWY PHY ZMNIEJSZ LICZNIK CTQS O LICZBĘ BAJTÓW TRANSMITOWANYCH ALBO W TRYBIE BEZ POTWIERDZENIA ALBO KIEDY RAMKA JEST POTWIERDZONA PO TRANSMISJI WARSTWY PHY ZMNIEJSZ LICZNIK CFTOS O LICZBĘ BAJTÓW TRANSMITOWANYCH ALBO W TRYBIE BEZ POTWIERDZENIA ALBO KIEDY RAMKA JEST POTWIERDZONA PO TRANSMISJI WARSTWY PHY S31 —χ KOMUNIKUJ ZLICZENIE TSQ DO SĄSIEDNICH PUNKTÓW AP KOMUNIKUJ ZLICZENIE CTQS DO SĄSIEDNICH PUNKTÓW AP S45-^ j, KOMUNIKUJ ZLICZENIE CFTOS DO SĄSIEDNICH PUNKTÓW AP FIG. 5 FIG. 6 FIG. 7 53/59P30829PL00 AP OD JEDNOSTKI WTRU(X) ODBIERZ DO S49 OD PUNKTU AP(X) S51 OD JEDNOSTKI WTRU(Y) OD JEDNOSTKI WTRU(Z) ODBIERZ INFORMACJĘ MAC MIB DO S54 DO S49 OD PUNKTU AP(Y) ODBIERZ SKALAR SL AP S52 ODBIERZ INFORMACJĘ MAC MIB S48 OCEŃ TSQ, CTQS I CSTQS OBCIĄŻENIA NIEOBSŁUŻONEGO RUCHU JAK RÓWNIEŻ OBCIĄŻENIA OBSŁUŻONEGO RUCHU ZARZĄDZAJ KANAŁEM DLA MAKSYMALNEGO WYKORZYSTANIA RUCHU I MINIMALNEGO BLOKOWANIA RUCHU (TZN. POPRZEZ DZIELENIE SEGMENTÓW ŁĄCZA UPLINK I ŁĄCZA DOWNLINK W CZASIE RAMKI TSQ W CELU OTRZYMANIA LEPSZEJ RÓWNOWAGI — S50 DO S54 OD PUNKTU AP(Z) FIG. 9 UTWÓRZ SKALAR OBCIĄŻENIA USŁUGOWEGO (SL) PUNKTU AP S50A OGŁOŚ SKALAR OBCIĄŻENIA USŁUGOWEGO SL PUNKTU AP S50B FIG. 8 53/59P30829PL00 OKTETY: 112 1 1 2 FIG. 10 WSKAŹNIK KATEGORII ŚREDNIE OPÓŹNIENIE DOSTĘPU (AGI) DOSTĘPU (AAD) OKTETY: FIG. 11 FIG. 12
Independent claims27
279 paragraphs in 22 sections, as filed
Description
[0001] FIELD OF THE INVENTION
[0002] The present invention relates to the field of wireless communication. More particularly, the present invention relates to wireless local area network (WLAN) systems that employ a link multiple access mechanism with channel state inspection and collision avoidance (CSMA / CA) and provides a means for congestion determination and management, and further improves network management by providing new control layer measurements. Medium Access (MAC) in wireless communication.
[0003] BACKGROUND OF THE INVENTION
[0004] Wireless communication systems are well known in the art. Basically, such systems include communication stations that transmit and receive wireless communication signals with each other. Depending on the type of system, communication stations are typically one of two types: base stations or wireless transceiver units (WTRUs) that include mobile units.
[0005] The term base station as used herein includes, but is not limited to, a base station, Node B, site controller, access point, or other interface device in a wireless environment that provides WTRUs with wireless access to a network with which the station is base is related.
[0006] The term WTRU as used herein includes, but is not limited to, user equipment, mobile station, fixed or mobile subscriber unit, pager, or any other type of device capable of operating in a wireless environment. WTRUs include personal communication devices such as, for example, telephones, videophones, and prepared telephones
53 / 59P30829PL00 working with the Internet that have network connections. In addition, the WTRUs include portable personal computing devices such as, for example, PDAs and notebook computers with wireless modems that have similar network capabilities. WTRUs that are portable or otherwise able to change their location are referred to as mobile units. Basically, the base stations are also WTRUs.
[0007] Typically, a network of base stations is provided in which each base station is capable of running concurrent wireless communications with appropriately configured WTRUs. Some WTRUs are configured to conduct wireless communication with each other directly, that is, without being communicated over the network via the base station. This is commonly known as peer-to-peer wireless communication. When the WTRU is configured to communicate with other WTRUs, the WTRU itself may be configured as a base station and also function as a base station. The WTRUs may be configured for use in multiple networks with both network and peer-to-peer communication capabilities.
[0008] One type of wireless system, called a wireless local area network (WLAN), may be configured to conduct wireless communication with WTRUs having WLAN modems that are also capable of peer-to-peer communication with similarly equipped WTRUs. Currently, WLAN modems are integrated by manufacturers in many traditional communication and computing devices. For example, mobile phones, personal digital assistants (PDAs), and notebook computers have one or more WLAN modems built-in.
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[0009] A common local area network environment with one or more WLAN base stations, typically referred to as access points (APs), is built according to the IEEE 802.11 family of standards. An example of an 802.11 local area network (LAN) as shown in Figure 1 is based on an architecture in which the system is partitioned into cells. Each cell includes a Basic Service Set (BSS) that includes at least one AP for communicating with one or more WTRUs, which are generally referred to as stations (STAs) in the context of 802.11 systems. Communication between the AP and the STAs follows the IEEE 802.11 standard, which defines an air interface between a wireless STA and a wired network.
[0010] A wireless LAN (WLAN) may be formed by a single BSS with a single AP having a distribution system (DS) portal. However, installations are usually made up of several cells and the APs are connected through a backbone called the DS system.
[0011] Figure 1 also shows an ad hoc mobile network (MANET). The MANET network is a self-configuration network of mobile routers (and associated hosts) connected by wireless links - the relationship of which creates any topology. Routers are free to randomly move and organize themselves freely; therefore, the topology of the wireless network can change rapidly and unpredictably. Such a network may work alone or it may be connected to a larger Internet.
[0012] An interconnected WLAN including various cells, their respective APs and a DS system is seen as a single IEEE 802.11 network and is referred to as an extended service set (ESS). IEEE 802.11 networks typically use a multiple access protocol to the survey link
Channel status and collision avoidance (CSMA / CA) for wireless information exchange between nodes (or STAs) of the WLAN. In such a configuration, STAs requesting transmission must contend for access to the wireless bearer. The contention mechanism involves waiting for the bearer to remain free for a certain period of time (according to a set of rules defined by the standard) before transmitting the data packet. The time it takes for a node to access a channel and transmit its data packet increases as the number of stations and traffic increase. Congestion in such a system can occur when bearer access times become unacceptable with too many stations competing for the same bearer.
[0013] Due to the nature of the CSMA / CA protocol and considering that most transmissions are not best-effort guaranteed, it is quite difficult to determine when a system is classified as experiencing congestion. Identifying congestion in such a complex system is not a straightforward task as one selection of metrics may indicate congestion while another metric will not indicate congestion.
[0014] Several metrics that may be used to indicate congestion include: collision frequency, channel utilization, ie the time the bearer is busy, etc. However, when considered individually, these metrics do not necessarily give a true congestion picture. For example, the metric of channel utilization does not give an accurate picture of the congestion situation. One station can be alone on the channel and transmit all the time. In this case, the channel usage metric will be high. This may appear as if the system is unable to handle more traffic from other stations. However, if a new station were to access the channel, it would still experience good bandwidth due to the CSMA / CA mechanism because then
The channel would be equally shared between the two stations. The system is in fact crowded when there are many stations competing for the same channel at any given time and experiencing severe delays due to the fact that each station has to wait longer to access the bearer as well as due to a greater number of collisions.
[0015] In another aspect, there is currently limited network management functionality, especially in IEEE 802.11 and IEEE 802.lik compliant systems. The inventors have noted that there are certain limitations to the usability of the channel load information currently used in the context of network management. There is also a need for an improved method of achieving better network management taking into account the constraints on the use of channel load measurements. The present invention provides an improved network management related to the IEEE 802.11 and IEEE 802.lik standards in the context of channel load information.
An example can be found in EP 1156623.
[0016] SUMMARY OF THE INVENTION
[0017] The present invention provides a method for determining and reporting congestion in a Wireless Local Area Network (WLAN) system. One aspect of the present invention applies to wireless systems that use CSMA / CA. Preferably, several metrics are used to determine congestion, including: average backoff time, in-BSS deferral rate, out-of-BSS deferral rate, number tied stations, average channel utilization by WTRUs, and average media access control (MAC) buffer occupancy. Actions taken to alleviate congestion preferably include sorting the set of WTRUs in order of the greatest amount of time lost trying
Acknowledge / unacknowledged packet transmissions, and disconnect the WTRUs one at a time until congestion mitigation is achieved.
[0018] The methods are preferably implemented according to the appended claims 1-27.
A more detailed understanding of the invention can be obtained from the following description of the preferred embodiments, given by way of example and understood together with the accompanying drawings.
[0020] BRIEF DESCRIPTION OF THE FIGURES
[0021] Figure 1 is an overview diagram of a conventional IEEE 802.11 WLAN with their respective components.
[0022] Figures 2-9 are flow charts illustrating the media of the present invention for determining and managing congestion in wireless communication systems. Especially:
[0023] Figures 2 and 2A together show a method of determining congestion using deferral rate (DR) and packet error rate (PER) metrics, and WTRU decoupling based on determining wasted time trying to transmit / retransmit unacknowledged packets.
[0024] Figure 3 illustrates a load reduction management method by comparing a node's load with the announced loads on neighboring nodes.
[0025] Figure 4 illustrates a method of delivering the announced load to WTRUs based on the average delay between the time a packet reaches the queue front and the transmission of that packet.
[0026] Figures 5, 6 and 7 illustrate a method for providing transmit queue size (TQS), transmit queue size without contention (CTQS) and transmit queue size with contention (CTQS), respectively, to neighboring nodes, respectively.
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[0027] Figure 8 illustrates a method used by a channel management node based on estimating handled and unhandled traffic from WTRUs and providing a service load scalar to advertise to WTRUs.
[0028] Figure 9 illustrates the method used by WTRUs to select a node based on load scalars provided by neighboring nodes.
[0029] Figure 10 is a diagram of the BSS load element format according to the present invention.
[0030] Figure 11 is a diagram of the format of the service load item of access category according to the present invention.
[0031] Figure 12 shows a communications station configured in accordance with the present invention.
[0032] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] Although the features and elements of the present invention are described in the preferred embodiments in specific combinations, each feature or element may be used separately (without the other features or elements of the preferred embodiments) or in various combinations with or without the other features and elements of the present invention. invention.
[0034] One aspect of the present invention introduces two different approaches to determining a channel congestion bias metric; first, a load metric based on Basic Service Set (BSS) which is mainly based on the load on individual APs. Second, the channel based load metric, which is a metric that indicates the load shared between different APs.
[0035] BSS based load metrics are metrics that determine high load condition and channel congestion. The two preferred BSS-based load metrics are the intra-BSS lag factor metric and the packet error rate metric.
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[0036] The Deferral Rate (DR) is a measurement that represents the percentage of time the AP receiver is locked to the bearer (i.e., the Clear Channel Assessment (CCA) function indicates busy status), while the AP has one or more packets to transmit (i.e., its queue is not empty). In other words, the DR ratio represents the amount of time the AP spends deferring transmission to other nodes in the WLAN.
The intra-BSS deferral factor represents the percentage of time the AP receiver is carrier-locked on a packet within the BSS (i.e., a packet originating from one of its associated WTRUs) while the AP has one or more packets. for transmission. In other words, the DR factor inside the BSS represents the amount of time the AP spends postponing its own transmissions because one of its associated WTRUs has taken control of the bearer (i.e., transmitting the packet).
[0038] The deferral factor within the BSS indicates the level of the current load on the system, and when there is a need to transmit to another node in the same BSS, it measures the time spent deferring the transmission. A low deferral metric value within the BSS indicates that the overhead for the BSS is low. A large value of the deferral factor within the BSS indicates that there are many transmitting nodes at the same time and therefore there is a significant overhead.
[0039] In the case where there are only two nodes in a system with a significant amount of data to transmit, the deferral factor may be high and if used alone it will indicate congestion. However, as there are only two nodes present in the system, this is not considered a congestion situation. In order to resolve this situation,
The present invention uses a packet error rate (PER) in addition to the lag factor metric.
[0040] The packet error rate (PER) is the ratio of the number of unsuccessful transmissions (i.e., transmissions of packets for which an ACK acknowledgment message was not received) to the total number of packets transmitted. The PER metric is a good indicator of the collision rate in the system when conservative data rates are used. The greater the number of nodes in the system, the greater the likelihood of collisions. The combined use of both an intra-BSS lag metric and a PER metric gives a better indication of the AP load than either metric used individually.
[0041] In the present invention, as shown in Figure 2, the lapse rate metric within the BSS and the PER metric are determined in steps S1 and S3, respectively, and are then averaged over a predetermined period of time (e.g. seconds) in steps S2 and S4, respectively. The average values of both metrics are used to signal the occurrence of congestion in steps S5 and S6. More specifically, when the lag factor (DR) metric inside the BSS exceeds a first predetermined threshold value determined in step S5 and the PER metric exceeds a second predetermined threshold value determined in step S6 for a defined period of time (e.g. 30 seconds). ), then it is an indication of congestion.
[0042] Regardless of whether or not the congestion is detected based on the criteria outlined above or using other techniques for determining the congestion, the present invention provides the following actions; first the AP in step S7 sorts all the WTRUs in the Basic Service Set (BSS) in order of the amount of time spent trying to retransmit. The lost time is preferably determined according to the lost time algorithm,
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ALG<sub>Tue</sub>as shown below. More specifically, a set or list of WTRUs with unacknowledged packets is created. For each unacknowledged packet into the WTRU, the sum of all wasted time spent trying to transmit and retransmit a packet (i.e. packet size / packet rate plus penalty for each retransmitted packet) is recorded. The loss reflects the incremental delay associated with retransmissions, that is, a backoff time due to a double congestion window (CW). The loss represents the added delay associated with the time from the moment the packet is ready for transmission to the moment when the packet is actually transmitted by the bearer. This retransmission time metric is thus much greater for time-wasting stations retransmitting after collisions. The retransmission time metric is normalized to the selected time interval.
[0043] An exemplary formula for determining wasted time for a WTRU is given by:
. Size pkt wasted _txtime<sub>WTRU</sub> = Σ Σ drrzzL · + RTx<sub>M.</sub> * Penalty taiackPkis i = l ^ Pkt _tX where: wasted _ time<sub>WTR0</sub> = sum of wasted time spent trying to transmit and retransmit unacknowledged packets to the WTRU j = j packet i = jth transmission of jth packet #_pktSj = number of transmissions of jth packet, e.g.
1, 2, 3, . . .
Pkt_sizeij = size in bits of the ith transmission of the j packet
Pkt_tx_rateij = bitrate in bps of the i-th transmission of this packet
53 / 59P30829PL00
R<sub>T.</sub>Xi> i
2<sup>1 2</sup>, for i> 1, otherwise O
Penalty
CW<sub>ml</sub> * slot time, for example CW<sub>min</sub> = 32 and the time of the aperture = 20ps
Attention:
CW will be 2 x CW<sub>min</sub> after the first transmission and.
Note that #_pktSj represents the number of unacknowledged transmissions of a given packet. If the packet is finally successfully transmitted, then #_pktSj corresponds exactly to the number of retransmissions. If the packet is discarded (that is, it was never successfully transmitted), then #_pktSj corresponds to (retransmission count + 1).
[0044] An example of the calculation of wasted_txtime<sub>S.</sub>The TA is given below: It is assumed that the AP has 20 packets to send to the specified STA. During the course of the transmission, the AP monitors and records whether the packet has been successfully acknowledged or not and the number of packet retransmissions, for example as follows:
GGGGGBBBUBBBUGGGGGilGGGGGGilBBBUGGGG
Where:
ίϊ = speed increase,
U = speed reduction,
G = confirmed or "good frame,
B = unconfirmed or "bad frame."
The first B-frame represents the sixth packet and there have been six transmissions of the sixth packet, ie BBBUBBB.
#_pkts<sub>6</sub> = 6
Pkt_sizei6 = 12,000 bits
Pkt_tx_rateie = {11.0, 11.0, 11.0, 5.5, 5.5, 5.5} Mbps
R<sub>T.</sub>x<sub>i> 1</sub> * Penalty = {0, 0, 640, 0, 1280, 0, 2560, 0, 5120, 0,
10240.0} με
53 / 59P30829PL00
The seventh box B represents
17th packet and there were three transmissions of this 17th packet, that is, ί U-U-.
#_pkts<sub>17</sub>
Sizem point = 8,000 bits
Point _ tx _ installment = {11.0, 11.0, 11.0} Mbps
R<sub>T.</sub>Xi> i * Penalty = {0, 0, 640, 0, 1280, 0} ps
Because:
wasted_txtime<sub>STA</sub> = (12000 / lle6) + (12000 / lle6 + 640.0) + (12000 / lle6 + 1280.0) + (12000 / 5.5e6 + 2560.0) + (12000 / 5.5e6 + 5120.0) + (12000 / 5.5e6 + 10240.0) + (8000 / lle6) + (8000 / lle6 + 640.0) + (8000 / lle6 + 1280.0) = 33.76 ms.
[0045] Preferably, the WTRUs are sorted from largest to smallest times in step S7-4. The program then moves to step S8. In step S8 (figure 2) each STA in the sorted list is disconnected with the longest time first until the congestion is alleviated.
[0046] The present invention also provides for the use of other metrics including: BSS based load metrics; the number of associated WTRUs, the time the access point (AP) receives all acknowledgment (ACKS) (for example, fragmentation) for that packet at the media access control (MAC) layer, and the average MAC buffer occupancy (based on buffer size) .
[0047] The present invention further provides a method that considers the load on adjacent APs when evaluating the needs of the system to perform any congestion reduction (i.e. disconnection) or load balancing. For example, as shown in figure 3, if the load on each of the adjacent APs is also high as accumulated in steps S9 and S10, and compared with the adjacent APs in steps S1 and S12, the reduction
The load is delayed (step S14) because the user would be unlikely to be served elsewhere, i.e. all of L1, L2 and L3 are large (step S13). The load reduction is performed in step S16 if L1 or L2 have lower announced loads (step S15B). If the load L3 is less than L1 and L2 then the AP may accept the WTRU as shown in steps S15A and S17.
[0048] In order to advertise a load to its stations (WTRUs), an access point (AP) may compare its load with respect to neighboring APs, i.e. AP (x) and AP (y), for example. When the load on the AP is large compared to the estimated load on its neighboring APs, then the AP announces a high load in response to the determination in step S15A (Figure 3). When the load on the AP is small compared to the estimated load on its neighbors, the AP announces a low load in response to the determination at step S15B.
[0049] Another method according to the present invention is to use metrics that determine the load on the medium (i.e. the channel). This metric allows the WTRU to select the least loaded AP. Bearer load metrics are used in cases where the channel load inside the BSS is not efficient, such as the case where a BSS with a channel load inside the BSS could simply be deferred to an adjacent BSS and therefore although the AP load is small, the load on the media is heavy. In this case, the posted load should be representative of the carrier load. In this case, the AP only announces a low load when it is able to handle the new WTRU.
[0050] The metric that gives an indication of the carrier load is the average duration (Avg D) required to perform the backoff which is determined in
The method of Figure 4 for downlink transmission at an AP. In particular, this metric represents the bearer access delay from when the packet is ready for transmission (i.e., CSMA / CA access contention starts) to when the packet starts transmission over the bearer, as defined in steps S18-S23. and by announcing Avg D to WTRUs in step S24.
[0051] The size of the contention window affects the time needed to perform the backoff procedure. The contention window size is increased as soon as no acknowledgment is received from the receiving node. This aspect includes cases where there are collisions either between nodes of the same BSS or different BSSs. During the countdown of the backoff procedure, the countdown is suspended as soon as the bearer is detected as busy, which increases the duration of the backoff procedure. This additional aspect covers cases where the bearer is heavily loaded due to WTRUs of own BSS and / or neighbor BSSs. Taken alone, this metric gives a good indication of the congestion perceived by this node in the BSS. One might consider simply using the time when media is busy (channel usage) as a metric. However, in an example where only one WTRU is associated with an Access Point (AP) and transmits or receives a large amount of data, the channel utilization metric will not give a good congestion indication. Channel utilization will indicate high congestion when the system actually serves only one user. A second user (WTRU) added to this AP can be easily served. In the single user example, the new proposed metric Avg D (i.e., the average duration of the backoff procedure execution) will surely indicate low congestion.
53 / 59P30829PL00
[0052] The Avg D metric is the preferred measure as the short duration required for the back-off procedure indicates a lightly loaded carrier, and a long duration indicates a heavily loaded carrier. Consider the current IEEE 802.llb standard as an example. The minimum value for the competition window (CW) is 32x20 με = 640 με, and the maximum value is 1023 x 20 με = 20.5 ms. However, the duration required to execute the back-off procedure may be greater than the maximum size of the CW window due to the suspend countdown due to bearer busy detection. This increase in duration will give an indication of the load due to activity in the carrier.
[0053] Reasons for using MAC load measurements in the context of the present invention include:
• The MAC layer has a lot of information that is not currently available through an information management base (MIB) or through measurements in the IEEE 802.11 and IEEE 802.lik standards.
• The new information items offered by the present invention that are useful for higher layers are not currently available, although they may be offered within the scope of the 802.lik standard.
• IEEE 802. How many channel utilization (CU) has been identified as a useful load information element.
[0054] The present invention also recognizes that there is a need for WTRU uplink load information and AP service load information. Some limitations of CU information include:
• The load information is useful for handoff (andoff) decisions at the WTRU and AP.
• The CU information of a potential destination AP is useful for the WTRU in evaluating call transfer options.
The CU is the sum of the load handled on the uplink (all WTRUs to the AP) and the load handled on the downlink (the AP to all WTRUs), also known as channel utilization.
• However, the traffic load consists of two parts:
traffic load handled and traffic load unhandled (queued).
• CU does not currently provide information about dynamic, unhandled, queued traffic.
[0055] The network currently does not have a way to access unhandled uplink traffic (queued traffic load).
[0056] Advantages of WTRU uplink traffic load (ULTM) load measurements in network management include:
• High channel load indicates that the traffic handled is close to maximum.
• If the demand for unhandled traffic is low, it means optimal channel management.
• If the demand for unhandled traffic is high, it means suboptimal channel management.
• The unhandled uplink traffic demand is very useful for allowing the AP to better subdivide the uplink and downlink time frame segments.
• APs must manage the channel for maximum traffic utilization and minimum traffic blocking.
• Queued uplink traffic in WTRUs indicates transmission delays and a potential channel lock.
• The volume of queued data in the MAC transmission buffers gives a good measure of the queued uplink load.
[0057] The present invention provides a new MAC management information base (MAC MIB) element for transmission traffic load, namely a Transmit Queue Size (TQS). The Transmission Queue Size (TQS) is defined as follows: The new MIB information contains three (3) elements: Total Transmission Queue Size (TQS) consisting of the sum of Contention-free TQS (CFTQS) Transmission Queue Size and Transmission Queue Size Contention TQS (CFTQS). [0058] The TQS contains the current MAC queue size in bytes.
The TQS may be included in the MAC MIB 802.11 Counters Table. The Dot1ICounters Table is a defined data structure in the standard. The TQS information may be implemented by a counter as shown in figure 5, the WTRU, in step S25, initializes the TQS counter to zero after starting the system. The WTRU in step S26 receives the frame and, in step S27, queues the frame at the MAC layer. In step S28, the WTRU increments the TQS counter by the number of bytes in the queued frame. Alternatively, accumulation can use a software technique where a count can be stored in memory and incremented by replacing the current count (PC) with PC + 1, for example, as each byte of the frame is sequenced.
[0059] The WTRU in step S29 transmits the Physical Layer (PHY) frame when the session is initiated and also, in step S30, it decreases the TQS counter by the number of bytes transmitted either while operating in the unacknowledged mode or when the frame is acknowledged by the AP after PHY transmission. The WTRU, in step S31, communicates the TQS count to adjacent APs. TQS is a new MIB component. All elements
MIBs are broadcast to neighbors as needed too
53 / 59P30829PL00 via a MIB query performed to obtain an item from a neighbor MIB.
[0060] A contention transmit queue size (CTQS) is implemented as for example shown in figure 6, where the WTRU, in step S32, initializes the CTQS with zero on system startup. The MAC layer of the WTRU, in step S33, receives a contention frame, and in step S34 it queues it in the MAC layer contention queue. In step S35, the CTQS counter is incremented by the number of bytes in the received frame.
[0061] The WTRU in step S36 transmits the frame (e.g. to the AP) using the PHY layer while operating either in the unacknowledged mode or when the frame has been acknowledged after PHY transmission, and in step S37 it decreases the CTQS counter by the number of bytes transmitted. either in the unacknowledged mode or when the frame is acknowledged after transmission of the PHY layer. In step S38, the WTRU communicates the CTQS count to adjacent APs.
[0062] Contention Free Transmission Queue Size (CFTQS) is implemented as shown in Figure 7 by providing a CFTQS counter, the WTRU in step S39 initializing the CFTQS counter with zero on system startup.
[0063] In step S40, the MAC layer of the WTRU receives a contention-free frame and queues that frame in a contention-free (CFQ) queue in step S41. In step S42, the WTRU increments the CFTQS counter by the number of bytes in the queued frame.
[0064] In step S43, the WTRU transmits the frame without contention using the PHY layer, and in step S44, it decreases the CFTQS counter by the number of bytes transmitted in the frame in the unacknowledged mode or when the frame is acknowledged after transmission of the PHY layer. In step S45, the WTRU communicates the counting to adjacent APs.
53 / 59P30829PL00
Figure 8 shows one method in which the AP uses MAC MIB information, where the AP for example in steps S46, S47 and S48, respectively, receives MAC MIB information including one or more TSQ, CTQS, and CFTQS counts from e.g. WTRU (x), WTRU (y), and WTRU (z). This data, which represents the unhandled traffic, is combined with data about served traffic, such as channel load, which includes both uplink and downlink loads, and is estimated by the AP which uses the load data in step S49 and in step S50. served and unhandled to manage the channel, such as by adjusting the traffic to maximize utilization and minimize traffic blocking. The AP may adjust segments of the uplink and downlink frame based on the uplink traffic unhandled data to optimize channel utilization.
[0066] Considerations for providing AP service load metrics in the context of the present invention include the following:
[0067] The WTRUs may consider multiple APs as destination APs for handoff. If the two APs have similar channel load and acceptable signal quality, the WTRU must be able to find out which AP is better. By allowing APs to announce information about their ability to support their existing set of WTRUs and their ability to support additional WTRUs, channel utilization can be optimized. This information is similar to a downlink traffic queue measurement for an AP modified by any AP specific information regarding its predicted capacity.
[0068] The problem of AP service load is solved below:
53 / 59P30829PL00
[0069] A new MAC MIB information element is provided to assist the WTRUs in their handoff decisions.
[0070] The quantification on a scale of 255 values (represented for example by 8 binary bits), from "does not currently support any WTRU to" cannot undertake any new services with a defined middle value indicating that the supported load is optimal. For example:
== does not support any WTRU (idle AP or WTRU is not AP) up to 254 == scalar AP service load indication 255 == unable to accept any new services
[0071] The exact specification of this MIB element is implementation dependent and need not be precisely defined; the detailed definition of obtaining maximum utility may be tailored to the characteristics of the network in question.
[0072] The new AP service load may be included in the MAC dot1ICounters Table or anywhere in the MIB.
[0073] A WTRU having a plurality of APs that can be selected as a destination AP, in addition to considering the channel load and acceptable signal quality as shown in figure 9, can receive load announcements from APs (x), AP (y) and AP (z) respectively shown in steps S51, S52 and S53, and in step S54 it evaluates the received announced AP loads (SL scalars) and thus is able to make a decision based on comparisons of the received announced AP loads, and in step S55 selects an AP.
[0074] The service load (SL) of the AP is a scalar value and may be based on e.g. handled and unhandled traffic as well as other data such as signal quality as well as projected capacity, e.g.
53 / 59P30829PL00 based on statistical data. SL point load scalar
The AP may be formed as shown in the step
S50A of Figure 8 and announced to the neighboring WTRUs as shown in step S50B.
[0075] The above methods are preferably implemented in selectively configurable WTRUs. For example, the WTRU may be configured to assist in channel management in a wireless network by providing memory devices, a processor, and a transmitter. The storage device is preferably configured to provide a data frame queue for the Medium Access Control (MAC) layer of the WTRU. The processor is preferably configured to determine queue size data representing a request for unhandled queued traffic in the corresponding WTRU. The transmitter is preferably configured to communicate queue size data to wireless access points (APs) whereby the receiving AP uses the queue size data to assist in channel management. Specifically, the processor is configured to initialize with a value of zero a count representing the size of the queued data at system startup and incrementing the count by the number of bytes in a frame when the frame is enqueued by the WTRU's Medium Access Control (MAC) layer. Preferably, the processor is configured to decrease the count by the number of bytes per frame when the frame is transmitted over the physical layer (PHY) of the WTRU in the unacknowledged mode. Alternatively, the processor may be configured to decrease the count by the number of bytes per frame when the frame is transmitted over the physical layer (PHY) of the WTRU when the frame has been acknowledged after the PHY transmission.
[0076] In such a WTRU, memory is preferably configured with contention and non-contention medium access control (MAC) queues, and the processor is
Configured to determine contention transmit queue (CTQS) size data representing the request of unhandled, queued traffic for the contested queue, contention-free transmit queue size (CFTQS) data representing the request for unhandled contention, and total queue size data transmissions (TQS) representing the unhandled request, Queued traffic for all data transmission queues of the Medium Access Control (MAC) layer.
[0077] Such a WTRU preferably also includes a receiver configured to receive service load indices from the APs derived from queue size data received by the APs from the WTRUs, and a controller configured to select an AP for wireless communication based on the received APs. load indicators.
An access point (AP) may be configured to provide channel management on a wireless network for both access points (APs) and wireless transceiver units (WTRUs) capable of wireless communication with APs on wireless channels. The receiver is configured to receive unhandled traffic request data received from WTRUs located within the range of the AP's wireless service. The AP preferably has a processor configured to calculate the service load index based on the unhandled traffic request data received from the WTRUs. A transmitter is present that is configured to announce a service load index to WTRUs within the service coverage of the AP's wireless service, so that WTRUs located within the service coverage of the AP's wireless service can use the announced service load index to assist in selecting the AP with which to communicate. wireless. At such an AP the receiver
Preferably, the processor is configured to receive the published service load indices from other APs, and the processor is preferably configured to use the announced service load indices received from other APs to assist in decisions to disconnect work-related WTRUs from communication with the AP.
[0079] In another embodiment, a wireless transceiver unit (WTRU) is configured to manage congestion in a wireless communication system defined by a Basic Service Set (BBS). The WTRU has a processor configured to determine a deferral factor (DR) within a Basic Service Set (in-BSS) and averaging said DR over a given time interval. Preferably, the processor is also configured to determine a packet error rate (PER) and average said PER value over said time interval. The memory is configured to store comparative values reflecting the time lost in an attempt to transmit data for each WTRU operatively associated with the WTRU in the BSS. There is a transceiver that is configured to disconnect the work related WTRUs from the WTRU starting with the WTRU having a comparison retained value reflecting the greatest time spent attempting data transmission when said DR average deferral rate and said PER packet average error rate are greater than the data. threshold values.
[0080] In such a WTRU, the processor is preferably configured to average the DR deferral rate and the PER packet error rate over a time interval of thirty seconds, and the transceiver is configured to periodically receive and update memory with comparative values reflecting the lost time.
Spent trying to transmit data for each entity
WTRU operatively associated with the WTRU.
[0081] In such a WTRU, the processor may also be configured to determine a comparison value of wasted time by measuring the time it takes for the WTRU to receive either a Successful Acknowledgment (ACK) or a Negative Acknowledgment (NACK) in response to a transmitted data packet, summing the measured times in during the beacon period and normalizing this sum over the beacon period. The transceiver is then preferably configured to periodically transmit current comparative values reflecting the time wasted attempting to transmit data to other WTRUs.
[0082] The AP may also be configured to assist wireless transceiver stations (WTRUs) in selecting the AP with which to wirelessly communicate in a wireless communication system by providing it with selectively configured components. Preferably, the receiver is configured to receive the advertised load indicators of other APs. A processor is present which is configured to compare the communication load of the AP with received advertised load rates from other APs and determine an adapted AP load based on said comparison. The transmitter is configured to announce an adapted AP load to the WTRUs. Preferably, the processor is configured to periodically perform said comparison and determine an operation to update the load that the transmitter announces to the WTRUs.
[0083] At such an AP, the transmitter may be configured to announce a low load when the processor determines that the communication load of the AP is low compared to
To advertise load on other APs, and to announce a high load when the processor determines that the communication load of the AP is high compared to the advertised load on other APs. Moreover, the processor may be configured to determine the communication load of the AP by measuring the delay between when a data packet is ready for transmission and when a packet is actually transmitted to the WTRU, averaging said delay over a given period, and using the average delay. to indicate the load.
[0084] In another embodiment, the base station is configured to disconnect the WTRUs from operative association with it when a congestion condition is detected in the wireless network. The base station has a processor configured to determine a wasted time (Tw) spent attempting to transmit / retransmit unacknowledged packets for each associated WTRU and to normalize the wasted time Tw for each associated WTRU over a given period of time. Memory is provided that is configured to store a list of associated WTRUs and their respective normalized wasted times. The transceiver is configured to disconnect the WTRUs to reduce said congestion based on their respective normalized wasted times, the WTRU having the highest wasted time Tw being disconnected first. Preferably, the processor is configured to add a loss to said time Tw representing the increasing delay associated with retransmissions, for example by being configured to calculate a wasted time (Tw) of transmission of the WTRUs according to the formula shown above.
[0085] The IEEE 802.Ile standard supports several categories of access, such as for example voice, video, unguaranteed
53 / 59P30829PL00 best effort as well as background traffic. In one embodiment, the present invention preferably uses the AP service load per access category. The BSS load element contains information about the current station population, traffic level and service level in the BSS. Figure 10 shows an example of element information fields according to the present invention.
[0086] The Length field should be set to the number of octets in the following fields. The Station Count field is interpreted as an unsigned integer that indicates the total number of STAs simultaneously associated with this BSS. The Number of Stations field should not appear in beacons or probe response frames if, for example, all dot1lQoSOption! Mplemented, dot1lQBSSLoad! Mplemented and dot1IRadioMeasurementEnabled elements are true.
[0087] The Channel Utilization field is defined as the percentage of time the AP detects busy bearer as indicated by either the physical or virtual medium discovery mechanism. This percentage is represented as a moving average of (( channel busy time / (dotllChannelUtilizationBeaconIntervals * dot1IBeaconPeriod * 1024)) * 255), where the channel busy time is defined as the number of microseconds during which the media discovery mechanism indicated channel busy and dotllChannelUtilizationBeaconIniltervals represents the number of consecutive beacon intervals over which this average should be calculated. The Channel Usage field will not be present in beacons or probe responses if all dot1lQoSOption! Mplemented, dot1lQBSSLoad! Mplemented and dot1IRadioMeasurementEnabled are true.
[0088] AP service load will be a scalar indication of the relative service load level at the AP.
53 / 59P30829PL00
A low value will indicate a more available service capacity than a higher value. A value of 0 will indicate that this AP does not currently serve any STA. Values between 0 and 254 will be a logarithmically scaled representation of the average media access delay for transmitted DCF packets measured from when the DCF packet is ready for transmission (i.e. CSMA / CA access begins) until actual transmission begins. package. A value of 1 will represent a delay of 50 με, and a value of 253 will represent a delay of 5.5 ms or any delay greater than 5.5 ms. A value of 254 will indicate that no AP service capacity is available anymore. A value of 255 will indicate that the AP service load is not available. The AP will measure and average the bearer access delay for all transmission packets using the DCF access mechanism over a specified time window, for example a thirty second measurement window. The accuracy of the average media access delay will be +/- 200 με or better averaged over at least 200 packets. [0089] Access Category (AC) Service Load (AC) may be provided in the BSS Load only at Quality-of-Service QoS APs (QAPs). The service load of the AC category will be a scalar indication of the Average Access Delay (AAD) at the QAP for the services of the indicated access category. A small value will indicate a shorter access delay than a higher value. A value of 0 will indicate that this QAP does not currently provide services for the indicated AC access category. Values between 0 and 254 will be a logarithmically scaled representation of the average bearer access delay for the transmitted packets in the indicated AC category, measured from the moment the EDCF packet is ready for transmission (i.e.
53 / 59P30829PL00
CSMA / CA) until the actual transmission of the packet begins. A value of 1 will represent a delay of 50 ms, and a value of 253 will represent a delay of 5.5 ms or any delay greater than 5.5 ms. A value of 254 will indicate that services in the indicated AC access category are currently blocked or suspended. A value of 255 will indicate that the AC service load is not available.
[0090] The QAP will measure and average the bearer access delay for all transmission packets of the indicated AC category using the EDCF access mechanism in a predetermined time window, for example a continuous thirty second measurement window. The accuracy of the average media access delay will be +/- 200 ps or better when averaging at least 200 packets. The service load of AC category is preferably formatted as shown in Figure 11 as two octet subelements, the first octet containing the AC Indication (ACI)) and the second octet containing the measured value of the average access delay AAD. for the indicated category AC. It should be noted that the octets shown in Figures 10 and 11 are provided by way of example only and any other octet may be used. Table 1 gives an example of ACI encoding.
Table 1
<td>Access Category (AC)</td><td>ACI</td>
<td>unguaranteed delivery (Best Effort)</td><td> 0</td>
<td>Background</td><td> 1</td>
<td>Video</td><td> 2</td>
<td>Voice</td><td> 3</td>
<td>Reserved</td><td> 4-255</td>
53 / 59P30829PL00
[0091] Referring now to Figure 12, there is shown a communications station 100 configured in accordance with the present invention. It should be noted that the communication station 100 may be an Access Point (AP), WTRU, or any other device capable of operating in a wireless environment. Communication station 100 preferably includes a receiver 102 configured to receive unhandled traffic request data from WTRUs located within the wireless service range 108 of communication station 100. Communication station 100 also includes a processor 104. Processor 104 is preferably coupled to receiver 102 and is configured to calculate the load element. BSS for each of the multiple access categories. Communications station 100 also includes transmitter 106. The transmitter 106 is preferably configured to advertise the BSS load element within the service range 108 of the communication station 100. The BSS load element may then be received by other communication stations (e.g., access points and / or WTRUs) within the service range 108 of the communication station 100 thus providing them with same in the information on BSS.
[0092] Examples
1. A method for providing channel management in a wireless network for optimizing network utilization by both access points (APs) and wireless transceiver units (WTRUs) capable of wireless communication with each other on wireless channels, comprising forming a service load index by the first AP for each access category.
[0094] 2. The method of example 1 further comprising publishing a service load index to the WTRUs within the service scope of the first AP.
[0095] 3. The method of any of the preceding examples further comprising the step of selecting an AP by the WTRU based on the service load index.
53 / 59P30829PL00
[0096] 4. The method of any of the preceding examples wherein the service load index is an average access delay indication at the first AP.
[0097] 5. The method of example 4, wherein the average access delay is measured over a predetermined period of time.
[0098] 6. The method of example 5, wherein the time period is thirty (30) seconds.
[0099] 7. The method of any of the preceding examples, wherein the access categories include voice, video, unguaranteed, and / or background traffic.
[0100] 8. The method of any preceding example, further comprising receiving the announced service load index from a second AP.
9. The method of example 8, further comprising using the announced service load indicator in the decision to disconnect the WTRUs by the second AP.
[0102] 10. The method of any of examples 8-9, wherein the second AP disconnects the WTRUs from the second AP, the service load index from the first AP being small compared to the service load index determined by the second AP.
[0103] 11. An access point (AP) configured to provide channel management in accordance with the method of any of the preceding examples.
[0104] 12. The AP of Example 11, comprising a processor configured to calculate the service load index for each access category.
[0105] 13. The AP of any preceding example, comprising a transmitter configured to announce a service load index to the WTRUs within the AP's wireless service range.
[0106] 14. An AP as claimed in any preceding example, wherein the WTRUs are located internally
The wireless service range of the AP may use the announced service load index to assist in selecting the AP with which to perform wireless communication.
[0107] 15. The AP of any one of the preceding examples, comprising a receiver configured to receive advertised service load indicators from other APs.
[0108] 16. The AP according to any of the preceding examples, wherein the processor is configured to use the advertised service load indicators received from other APs to assist in decisions to disconnect the WTRUs from the AP.
[0109] 17. A wireless transmit / receive unit (WTRU) configured to provide channel management in the wireless network in accordance with the method of any of the preceding examples.
[0110] 18. The WTRU of example 17 including a receiver for receiving a service load index for each access category from the AP.
[0111] 19. The WTRU according to any one of examples 17-18 comprising a processor configured to use the service load indicator in selecting an AP with which wireless communication should be performed.
20. A method for providing channel management in a wireless network for optimizing network utilization by communication stations capable of wirelessly communicating with each other over wireless channels, comprising a first communication station providing a Basic Service Set (BSS) load element for each of a plurality of access categories. .
21. The method of example 20, further comprising advertising the BSS load element to other communication stations within a service range of the first communication station.
53 / 59P30829PL00
[0114] 22. The method of any of examples 20-21, further comprising at least one communication station selecting a different communication station to communicate with based on the BSS load element.
[0115] 23. The method of any one of examples 20-22, wherein the load element BSS comprises an element identification field.
[0116] 24. The method of any one of examples 20-23, wherein the BSS load element comprises a communication station, AP, or WTRU service load field, wherein said communication station, AP, or WTRU service load field is a scalar indication of the relative. the service load level at the first communication station.
[0117] 25. The method of any one of Examples 20-24, wherein the BSS load element comprises a length field whose value is set to the total number of octets contained in all fields of the BSS load element.
[0118] 26. The method of any one of examples 20-25, wherein the BSS load element further comprises a station number field, said station number field being an unsigned integer that indicates the total number of communication stations associated with the current BSS.
[0119] 27. The method of any one of examples 20-26, wherein the first communication station is an Enhanced Quality of Service (QoS) Communication Station (QoS) or an Enhanced Quality of Service (QAP) AP.
[0120] 28. The method of example 27, wherein said BSS load element further comprises a service load field of an access category (AC), said service load field of an AC category being formatted as four sub-fields each to provide a scalar average delay indication. access (AAD) in QCS or QAP for services of one of the access categories.
53 / 59P30829PL00
[0121] 29. The method of example 28, wherein the service load field from AC category is included in the BSS load element only if QoS-Option-Implemented is true.
[0122] 30. The method of any one of examples 28-29, wherein the four sub-fields comprise an AAD for a guaranteed delivery field (AADBE), AAD for a background field (AADBG), AAD for a video field (AADVI), and / or an AAD for a voice field. (AADV0).
[0123] 31. The method of any one of examples 28-30, wherein a low AAD value indicates a shorter access time than a larger AAD.
[0124] 32. The method of any one of examples 28-31, further comprising setting an AAD value for a first of four subfields to an AAD value of a subfield that is adjacent to and situated to the right of said first subfield when QCS or QAP does not provide services for said subfield. access categories.
[0125] 33. The method of any of the preceding examples, further comprising measuring and / or averaging the Medium Access Delay (MAD) value for all transmission packets of the indicated access category.
[0126] 34. The method of example 33, wherein said MAD value is measured and / or averaged by an EDCF access mechanism over a continuous time window, the averaged MAD value having a predetermined accuracy range and being based on a minimum number of delay measurements. broadcast packets.
[0127] 35. The method of Example 34, wherein said time window is a thirty (30) second measurement window wherein the predetermined precision range is two hundred (200) ps and / or wherein said average MAD is based on at least two hundred transmission packet delay measurements.
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[0128] 36. The method of any one of examples 28-35, wherein the AAD value within a predetermined value range in one of the four subfields is a logarithmically scaled representation of an average MAD value for transmitted packets in an indicated access category, said average MAD value being measured from the moment when an EDCF packet is ready for transmission to the moment when that EDCF packet is actually transmitted.
[0129] 37. The method of example 36, wherein said value range is between zero (0) and two hundred fifty four (254).
[0130] 38. The method of any one of examples 28-37, wherein the predetermined AAD value in any of the four subfields indicates that QCS or QAP does not provide services to the indicated access category or to any higher priority access category.
[0131] 39. The method of example 39, wherein said predetermined AAD value is zero (0).
[0132] 40. The method of any one of examples 28-39, wherein other predetermined AAD values represent different mean MAD times.
[0133] 41. The method of any one of examples 28-40, wherein an AAD of one (1) represents an average MAD of fifty (50) gs.
[0134] 42. The method of any one of examples 28-41, wherein an AAD of two hundred fifty-three (253) represents an average MAD of five and a half (5.5) gs or more.
[0135] 43. The method of any one of examples 28-42, wherein an AAD value of two hundred fifty-four (254) indicates that services in the indicated access category are currently blocked.
[0136] 44. The method of any one of examples 28-43, wherein an AAD of two hundred fifty-five (255)
53 / 59P30829PL00 indicates that the service load of AC category is not available.
[0137] 45. The method of any of the preceding examples, wherein the BSS load element further comprises a channel utilization field.
[0138] 46. The method of example 45, wherein said channel utilization field defines a percentage of the time when the first communication station detects the transmission medium as busy as indicated by the medium detection mechanism.
[0139] 47. The method of Example 46, wherein the percentage of time is a moving average.
[0140] 48. The method of example 47, wherein the moving average is defined using at least one parameter selected from the group consisting of a channel busy time parameter, a channel usage beacon interval parameter, and / or a beacon period parameter.
[0141] 49. The method of any one of examples 47-48, wherein said moving average is defined as the product of the channel busy time parameter and two hundred fifty five (255) divided by the product of the channel use beacon interval parameter, the beacon interval, and the numbers one thousand twenty four (1024).
[0142] 50. The method of any one of examples 48-49, wherein the channel busy time parameter is defined as the number of microseconds over which the medium detection mechanism has indicated channel busy.
[0143] 51. The method of any one of examples 48-50, wherein the channel usage beacon interval parameter is defined as a number of consecutive beacon intervals over which the average may be calculated.
53 / 59P30829PL00
[0144] 52. The method of any one of examples 48-51, wherein the channel use field is included in a BSS load element, when at least one of the parameters: QoS Option-Implemented parameter and PBSS Load implemented parameter ( PBSS-LoadImplemented) is false.
[0145] 53. A method of determining a Medium Access Delay Time (MAD) for a single access to a communication station, the method comprising determining a first time when a data packet is ready to be transmitted.
[0146] 54. The method of embodiment 53, wherein said first time is the time when a link multiple access protocol with channel state intelligence and collision avoidance (CSMA / CA) is initiated.
[0147] 55. The method of any one of examples 53-54, including the step of determining a second time in which a request to transmit is performed for a physical layer (PHY) transmission process.
[0148] 56. The method of any one of examples 53-55 comprising determining a third time when said request to transmit is acknowledged.
[0149] 57. The method of any one of examples 53-56, including calculating the packet transmission time settings and an acknowledgment as the difference between the second time and the third time.
[0150] 58. The method of any one of examples 53-57, comprising calculating the total access time as the difference between the third time and the first time.
[0151] 58. The method of any one of examples 53-58 comprising calculating the MAD time by subtracting packet transmission time and acknowledgment from total access time.
[0152] 59. The method of any one of examples 53-59, wherein a request to transmit is preceded by handshake
53 / 59P30829PL00 Ready to Transmit / Ready to Receive Request-toSend / Clear-to-Send (RTS / CTS).
[0153] 60. A method for determining the MAD time for retransmission of a data packet.
[0154] 61. The method of example 60, including determining a first time that a data packet enters a Medium Access Control (MAC) queue.
[0155] 62. The method of any one of examples 60-61, including determining a second time that the data packet is on the front of a MAC queue.
[0156] 63. The method of any one of examples 60-62, comprising calculating the MAC queuing delay as the difference between the second time and the first time.
[0157] 64. The method of any one of examples 60-63, including determining the first retransmission time as the difference between the start time of the first transmission and the end time of the first transmission.
[0158] 65. The method of example 64, wherein said first transmission start time indicates the start of a first transmission of a data packet and said first transmission end time indicates the end of said first transmission without receiving a transmission acknowledgment.
[0159] 66. The method of any one of examples 60-64, including determining the time of the second retransmission as the difference between the start time of the second transmission and the end time of the second transmission.
[0160] 67. The method of example 66, wherein said second transmission start time begins after a backoff and backoff period and indicates the start of a second transmission of a data packet, and said second transmission end time indicates the end of said second transmission without receiving a transmission acknowledgment.
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[0161] 68. The method of any one of examples 60-67, including determining the time of the Nth retransmission as the difference between the start time of the Nth transmission and the end time of the Nth transmission.
[0162] 69. The method of example 68, wherein said start time of an Nth transmission starts after a backoff and backoff period and indicates the start of an Nth transmission of a data packet, and said end time of an Nth transmission indicates receipt of a transmission acknowledgment.
[0163] 70. The method of any one of examples 60-69, comprising calculating the total retransmission time as the sum of the first, second, and Nth retransmission times.
[0164] 71. The method of any one of examples 60-70, including determining a completion time, which end time indicates the time during which an acknowledgment is received.
[0165] 72. The method of any one of examples 60-71 comprising calculating the MAD time for a data packet as the difference between completion time and first time, minus MAC queuing delay, minus total retransmission time, the total divided by N.
[0166] 73. The method of any of examples 20-52, wherein the first communication station is an Access Point (AP), and wherein the characteristics of the BSS load element are configured for use internally and / or by the AP.
[0167] 74. The method of any one of examples 20-53, wherein any of the other communications stations is an AP.
[0168] 75. The method of any one of examples 20-54, wherein the first communication station is a WTRU, and wherein the features of the BSS load element are configured for use by the WTRU.
[0169] 76. The method of any one of examples 20-55, wherein any of the other communication stations within and / or through the WTRU.
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[0170] 77. The method of any one of examples 53-72, wherein the communications station is an AP.
[0171] 78. The method of any one of examples 53-72, wherein the communications station is a WTRU.
[0172] 79. A communications station configured to provide channel management in accordance with any of the methods of examples 20-52 and 73-76.
[0173] 80. A communication station according to embodiment 79 comprising a receiver configured to receive unhandled traffic request data from other communication stations within the wireless service range of said communication station.
[0174] 81. The communications station of any one of examples 79-80, including a processor configured to compute a BSS load element for each of the plurality of access categories.
82. A communication station according to any of examples 79-81, comprising a transmitter configured to advertise a BSS load element to other communication stations within a service range of said communication station.
[0176] 83. The communications station of any one of examples 79-82, wherein the receiver is configured to receive advertised BSS load elements from other communication stations.
[0177] 84. The communications station of any one of examples 79-83, wherein the processor is further configured to use received BSS load elements from other communications stations to assist the communications stations in disconnecting decisions.
[0178] 85. The communications station of any one of examples 79-84, wherein said communications station is an AP.
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[0179] 86. The communications station of any one of examples 79-84, wherein said communications station is a WTRU.
[0180] 87. The communications station of any one of examples 79-86, wherein any of the other communications stations is an AP.
[0181] 88. The communications station of any one of examples 79-87, wherein any of the other communications stations is a WTRU.
[0182] 89. A communications station configured to determine the bearer access delay in accordance with any of the methods and / or features of Examples 53-72 and 77-78.
[0183] 90. The communications station of Example 89, wherein said communications station is an AP.
[0184] 91. The communications station of Example 89, wherein said communications station is a WTRU.
[0185] 92. A communications station according to any of examples 90-91, comprising a processor configured to determine the bearer access delay according to any of the methods and / or features of examples 53-72 and 77-78.
[0186] 93. A method for determining an average MAD time within a predetermined duration period, comprising defining a duration.
[0187] 94. The method of example 93, comprising determining the total duration of a packet transmission by summing the duration of the packet transmission and the time spent waiting for and / or receiving an acknowledgment for the number of packet transmissions occurring during said duration.
[0188] 95. The method of any one of examples 93-94, wherein the packet transmissions include packet retransmissions.
[0189] 96. The method of any one of examples 93-95, including determining a total empty transmission queue time for multiple access categories.
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[0190] 97. The method of any one of examples 96, wherein the total time of an empty transmission queue includes periods of time during which access category transmission queues remain empty.
[0191] 98. The method of any one of examples 93-96, comprising subtracting the total transmission duration of a packet, total empty transmission queue time, and / or total transmission queue deferral time from the duration to obtain the total difference.
[0192] 99. The method of any one of examples 93-97 comprising dividing the overall difference by the number of packet transmissions to obtain an average MAD time.
100. The method of any one of examples 93-99, including determining an overall transmission queue defer time for a plurality of access categories, wherein said transmission queue defer time includes periods of time during which access categories have deferred their respective transmissions to higher priority queues. .
[0194] 101. The method of example 100 comprising subtracting said total transmission queue delay time from the total difference before said total difference is divided by the number of packet transmissions to obtain an average MAD time.
[0195] 102. A communications station configured to derive the MAD time according to any of the methods and / or features of Examples 93-101.
[0196] 103. Communication station according to example 102 including a processor.
[0197] 104. The communications station of any one of examples 102-103, wherein said communications station is an AP.
[0198] 105. A communications station according to any one of examples 102-103, wherein said communications station is a WTRU.
53 / 59P30829PL00
[0199] While the present invention has been specifically illustrated and described with reference to the preferred embodiments, it should be understood that those skilled in the art will understand that various changes in form and detail may be made without departing from the scope of the present invention described above.
Contents22
12 sheets
Sheet 1 Sheet 2 Sheet 3 Sheet 4 Sheet 5 Sheet 6 Sheet 7 Sheet 8 Sheet 9 Sheet 10 Sheet 11 Sheet 12
86 members in 22 offices
Priority claims2
| Document | Office | Kind | Date |
|---|---|---|---|
| 93978504 | United States of America | A | |
| 2005032605 | United States of America | W |
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| US2005157676A1 | United States of America | A1 | |
| AU2005284886A1 | Australia | A1 | |
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| CA2862184A1 | Canada | A1 | |
| WO2006031834A2 | World Intellectual Property Organization (WIPO) | A2 | |
| DE202005014458U1 | Germany | U1 | |
| KR20060051271A | Republic of Korea | A | |
| TW200618549A | Taiwan Province of China | A | |
| TWM292848U | Taiwan Province of China | U | |
| WO2006031834A3 | World Intellectual Property Organization (WIPO) | A3 | |
| AR050799A1 | Argentina | A1 | |
| MX2007003012A | Mexico | A | |
| MX2007003012A | Mexico | A | |
| EP1792504A2 | European Patent Office (EPO) | A2 | |
| NO20071847L | Norway | L | |
| CN2914503Y | China | Y | |
| IL181894A0 | Israel | A0 | |
| IL181894D0 | Israel | D0 | |
| EP1792504A4 | European Patent Office (EPO) | A4 | |
| JP2008512975A | Japan | A | |
| BRPI0515662A | Brazil | A | |
| BRPI0515662A | Brazil | A | |
| CN101390412A | China | A | |
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| HK1126068A1 | Hong Kong, China | A1 | |
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| AU2005284886B2 | Australia | B2 | |
| AU2010200010A1 | Australia | A1 | |
| SG158134A1 | Singapore | A1 | |
| EP2259630A2 | European Patent Office (EPO) | A2 | |
| EP2259630A3 | European Patent Office (EPO) | A3 | |
| US8005055B2 | United States of America | B2 | |
| KR20110102253A | Republic of Korea | A | |
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| JP2012029333A | Japan | A | |
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| EP1792504B1 | European Patent Office (EPO) | B1 | |
| GEP20125577B | Georgia | B | |
| AU2010200010B2 | Australia | B2 | |
| DK1792504T3 | Denmark | T3 | |
| AU2012244209A1 | Australia | A1 | |
| KR20120125442A | Republic of Korea | A | |
| ES2391280T3 | Spain | T3 | |
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| JP2013081261A | Japan | A | |
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| KR101260215B1 | Republic of Korea | B1 | |
| KR20130052585A | Republic of Korea | A | |
| TW201325147A | Taiwan Province of China | A | |
| CN101390412B | China | B | |
| TW201336270A | Taiwan Province of China | A | |
| TWI410081B | Taiwan Province of China | B | |
| CN103327574A | China | A | |
| CN103369589A | China | A | |
| KR20130131263A | Republic of Korea | A | |
| MY150176A | Malaysia | A | |
| JP5441958B2 | Japan | B2 | |
| KR20140035463A | Republic of Korea | A | |
| TWI434548B | Taiwan Province of China | B | |
| JP5496164B2 | Japan | B2 | |
| KR101401709B1 | Republic of Korea | B1 | |
| KR20140088054A | Republic of Korea | A | |
| JP2014143764A | Japan | A | |
| JP5575937B2 | Japan | B2 | |
| CA2580311C | Canada | C | |
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| US8953573B2 | United States of America | B2 | |
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| KR101533527B1 | Republic of Korea | B1 | |
| JP2015195595A | Japan | A | |
| TWI511498B | Taiwan Province of China | B | |
| JP5832589B2 | Japan | B2 | |
| TWI514820B | Taiwan Province of China | B | |
| EP2259630B1 | European Patent Office (EPO) | B1 | |
| CN103327574B | China | B | |
| CN103369589B | China | B | |
| DK2259630T3 | Denmark | T3 | |
| EP3133776A1 | European Patent Office (EPO) | A1 | |
| NO340056B1 | Norway | B1 | |
| US9743313B2 | United States of America | B2 | |
| US2017325122A1 | United States of America | A1 |
Numbers
- Application
- 5797701
Titles2
- English
- METHODS, ACCESS POINT AND WIRELESS TRANSMIT/RECEIVE UNIT TO GENERATE A BASIC SERVICE SET
- Polish
- Sposoby, punkt dostępowy i bezprzewodowa jednostka nadawczo/odbiorcza do generowania podstawowego zestawu usługowego
Classification
- CPC, 16
- H04W28/0205
- H04W28/0284
- H04W28/14
- H04W48/08
- H04W48/12
- H04W48/20
- H04W72/00
- H04W74/08
- H04W48/18
- H04W28/0289
- H04W28/0942
- H04L47/10
- H04W72/0453
- H04W88/02
- H04W72/27
- H04W72/30
- IPC, 8
- H04W48 18
- H04W28 08
- H04W28 14
- H04W48 08
- H04W48 12
- H04W48 20
- H04W72 00
- H04W74 08
