Method for the operation of wireless base stations for packet transfer radio systems having a guaranteed service quality

Translation of description of equivalent WO 0130024 A2

SI, SK, SL, TJ, TM, TR, TT, TZ, UA, UG, US, UZ, VN, Published: YU, ZA, ZW - Without international search report and to publish again after receiving the report

(84) Designated States (regional): ARIPO patent (GH, GM, KE, LS, MW, MZ, SD, SL, SZ, TZ, UG, ZW), eura- maltese Patent (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), Europaisches Patent (AT, BE, CH, CY, DE, DK, ES, FI, to explain the two-letter codes and the other FR, GB, GR, IE, IT, LU , MC, NL, PT, SE), OAPI patent abbreviations is on the statements ( "Guidance Notes on (BF, BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, codes and Abbreviations ") referenced PCT Gazette at the beginning of each regular issue SN, TD, TG)

(57) Abstract: A method for Betneb wireless base stations for packet-switched radio systems with guaranteed service Good Novel method for increasing the supply range packet ones oriented transmitting radio stations that are not within the reach of a central base station and wireless base stations (relay stations) to be supplied Unlike ubhchen wirelessly transmitted systems is this a service the best for communication relationships guarantees The invention uses a common time my other cross Kapazitatsvergabe The Kapazitatsvergabe for from a base station (AP) directly attainable Stationenen (MT, FMT) is realized by AP Individual MTs act as wireless base stations and serve as relay stations ( fmts) against MTs out of range of an AP, compared with the Aps the fmts appear as MTs the FMT forms eme subframe structure in a part of the allocated by the AP transmission capacity, which is embedded in the predetermined by the higher central station timeframe structure compliance with the required Good service is guaranteed by suitable Kapazitatsvergabealgonthmen realized wireless, packet-oriented ones radio networks A method of operation of wireless base stations for packet-switched radio systems with guaranteed service Good

Technical field

The invention relates to a novel method of increasing the supply range packet-transmitting radio stations that are not within the reach of a central base station and are powered by wireless base stations with relay function. Unlike conventional wireless systems transferred here a verzogerungsdauer etc. characterized by parameters such as throughput, Paketverzogerungsdauer, variation in package service Good communication relations is guaranteed. Practical Einsatztelder such systems can include:

Local networks for data and multimedia communications, access networks to telecommunication networks,

Networks for connecting stationary and mobile subscribers and mobile subscribers with one another.

State of the art

In FUTURE radio systems to the user of a telecommunications service are provided dynamically different services to V. These services differ in the demands on the service good and the benotigte transmission capacity. For the allocation of the transmission of data (incl. Video and audio) NECESSARY capacity to ubertragungswilligen stations are different approaches in radio systems known:

Uncoordinated access (eg HIPERLAN Type 1 [3] or IEEE802. Il [7]). Here, the ubertragungswilligen stations engage initially uncoordinated to a radio channel. A coordination results from a decentralized strategy - 2 -

the allocation, without a central procurement service Good can be guaranteed in these systems only with a certain probability or not

Code / frequency range at a ubertragungswillige station, can be distinguished Exclusive allocation of transmission capacity in the time / two main groups

The capacity is verbindungsoπentiert using a channel fixed transmission rate allocated and is thus also simultaneously reserved exclusively for the duration of the connection (eg GSM [2] except GPRS [4]) - The capacity is dynamically by the base station _je as needed

[8] [1] [5] [4] assigned to the individual associated stations, vielzellulare systems are possible. This assignment is controlled by a central station, which is either initial known [5] or determined by a system itself is [6] In order to service good guarantee, special measures (connection acceptance and scheduling, [8]) are necessary

Shortcomings of previously known VERSIONS and task

In the next part is to wireless networks with centralized control received an allocation of transmission capacity through a central registry for a send / received fangswilhge station (MT closely Mobile Terminal A mobile terminal, but that can also be operated stationary) is only possible if the MT in the coverage area of ​​the base station is a not in the coverage area befindliches MT is RMT (eng remote Mobile terminal a MT whose Funkfeldverhaltnisse no direct radio link to the AP permit the RMT can advanced features compared to the MT own) called reason for inadequate radio coverage of the RMT can, inter alia, a great distance from the central base station (AP closely Access Point a central station, which may be stationary or movable This station organizes its associated network, the role of the central station can change in some systems (eg Adhoc in HIPERLAN 2 [6]) Can be), electromagnetic interference, level burglaries by shadowing of the radio waves by obstacles and multipath the - 3 -

RMT but the data of another station (FMT:.. Closely Forwarder Mobile Terminal A MT which can additionally assume the functions of a relay station, and thereby the wireless base station.), Which maintains a direct or indirect connection to the AP, received in sufficient quality and send data to this, then the RMT can be controlled according to the invention by the base station.

The new process controls communication between FMT and MT or RMT aiming the RMT equate concerns are eligible QoS a MT.

The procedure allows the sequential concatenation of multiple relay links such as AP ^«→ FMT <→ ... <→ FMT <→ RMT. An FMT behaves toward the parent FMT that the AP is closer like a MT and against the subordinate FMT as an AP.

Inventive Problem Solving

The invention uses a common time interlocking capacity allocation. The allocation of capacity directly accessible from the AP stations (FMT, MT) from the base station (AP) realized (Ex. [5]). This is the first radio hop (HOP), counted from the base station. It may be an active or passive (sleeping), connection-oriented or connectionless packet-oriented data connection or signaling connection. The control data of the AP to the availability of the radio channel by AP, MT and FMT of the first hops are cyclically, at predetermined intervals or dynamically dispatched to each announced or known distances. The AP allows all MTs and FMT in his Versorgunsgbereich random access, the success of the access is explicitly or implicitly to the stations. Collisions mechanisms are used for collision resolution. This type of dynamic capacity allocation is the art and exemplified in [1] [8] [5] set out.

This type of channel assignment is in this invention by expanding that individual MTs act as wireless base stations and thereby as a relay station (FMT) used and compared occur over RMTs as APs, but appear over APs as MTs

The FMT uses the allocated by the AP transmission capacity partly for their own purposes, sometimes to the controlled from FMT RMT transmission to the AP over a second radio link to the same or similar rules allow, as applied by the AP

Each as FMT used relay station forms to turn a part of the framework in which is embedded in the framework set by the parent central station structure. Only the FMT the assigned Kapaziat is used for the sub-frame structure used The structure of the sub-frame structure is the frame structure similar to the parent, so that a communication with unchanged MTs, but also to specially adapted stations. can D h. the sub-frame structure contains turn areas where Kapazitatsbelegungen be announced will provide answers to random accesses GE, a data transfer to the MT (bzw.RMT) held (Remote-down hnk) and a data transfer from the MT (or can take place RMT) for FMT (remote uplink). Also, a random access is made available. The division into sub-frame structures can be done recursively, ie multiple relay links are cascaded. The control of communication and Kapazitatsbelegungen on the individual hops can be done by

Through the base station (AP), which controls the transmission capacity for all with her directly or indirectly, that is connected by relay links or cascaded relay connections stations the relay stations (FMT) falls so the task of the person designated by the base station reservation of transmission capacity to the RMTs weiterzuvermitteln and build the subframe accordingly.

Independently by the AP for its MTs and fmts and by fmts for their RMTs Each FMT concerned from AP capacity and manages them independently as an AP This can with existing systems (eg H / 2 [5]), which for this FMT be assigned Uphnk area This procedure has the advantage that in existing systems (especially AP and MT) no change must be made, because the sub-frame structure fully integrated into the existing Rah-menstruktur It is only the new features of the FMT added the the FMT allocated transmission capacity is largely autonomously managed by the FMT and organized so that the RMT on the FMT reach the AP , or from the AP to achieve

Any combination of control by FMT and AP

For the realization of the FMT is due to the temporal structure, ie the allocation of transmission capacity in a time frame structure and Unterghederung in more temporal subframes structures only one transmitting / receiving part sufficiently If necessary, can multiple transmitting / receiving parts per FMT used The length of the frame of the AP and subframe the FMT can dynamically vary and different lengths also a dynamic rearrangement of the phases within the frame is possible, which also includes the lack of individual phases, and the use of new phases Further phases for data transmission to the broadcast mode (point-to-multipoint) operated its In addition to this mode, it is possible to organize a direct data transfer between individual RMT and between RMT and MT that does not work as FMT

In addition to the allocation of areas (TDMA) for the sub-frame is also an allocation of radio spectrum (FDMA) and Code fields (CDMA) is possible crucial that the central Basisstaπon that her standing for disposal capacity decomposed into Teilkapazitaten, which in turn each relay stations ( FMT) are assigned to this end, the administration described above of these partial regions and the allocation of individual pieces of these portions is respectively at the MTs RMTs used in appropriate systems (eg BH / 2-adhoc [6]) may additionally each MT to AP, which is relatively this reflects RMTs

With suitable Funkverhaltnissen it is with the help of the presented method is also possible to perform a spatial allocation of transmission capacity so that the sub-frame structure is used in parallel in different places of the centralized network For ensuring a required service good the possibility of controlled and organized allocation of transmission capacity requirement Compliance with the service good is for the units (AP, FMT) that control a distribution of them verfugbaren capacity for the transmission of each station is Appropriate policies are in their basic features already known [8] and can be adapted for this invention the NECESSARY changes made in the consideration of benotigten capacity for the organization of each sub frame structures as described above

exemplary

An exemplary embodiment is shown in the drawings and will be described below the near As an example of the invention is show in further expansion of the HIPERLAN 2 (H / 2) system [5] It considers

Figure 1 is a applicable for the invention scenario, the arrangement of the respective stations, Figure 2 or known from the H / 2 system frame structure on the radio interface and Figure 3 is relevant to the invention the frame structure as described in this invention as an example of H / 2 is proposed

In Figure 1, we demonstrated an exemplary situation as it can occur in packet radio networks Here, a H / 2 system is shown in the so-called "centralized mode" works D h each terminal of the system by the base station (AP) controlled addition are it can communicate the "direct mode" in the mobile terminal under the control of the AP directly to each other, the direct mode assumes that all terminals of a cell can receive the overhead information of the AP directly Assuming that r is the radius of the cell, in the individual MTs can receive the AP and can exchange information with the AP, the RMTs outside this range are not prepared following Funkverhaltnisse able to exchange data with the AP The invention contemplates solutions to connect RMTs on APs. The prerequisite is that the RMT is r within the radius_{ is a MT. These MTs are then used as relay stations (FMT), which form a bridge between AP and RMT and can transmit data bidirectionally. The transmission of data is controlled by the AP in H / 2 system. Given a periodic frame structure is transmitted, which is divided into different sections. In Figure 2, the temporal structure is shown as it is used in the H / 2 system.

First broadcast channel (broadcast channel) will be sent general information about the cell and the associated AP in so-called.. Subsequently sent the AP

Organisation data FCCH (Frame Control Channel) on the future availability of the remaining MAC frame whose total length in H / 2 is constant at 2 ms. In the following ACH (Acknowledgement Channel, acknowledgment channel) terminals of the success of the access is related. Communicated to the declared in the following channel for random access. This is followed by downlink phase follows, will be sent in the data from the AP to the individual MTs. This data is sent in long protocol data units of 54 bytes (LCH, Long Channel) or short data units of 9 bytes (SCH, Short Channel). Additionally, it is possible to combine the individual units of data to data trains. In the uplink phase, the individual mobile terminals opportunity to send their data to the AP. At what point must send each terminal is already indicated in the FCCH. At the end of the MAC frame, there is a period where all the terminals according to certain rules arbitrarily allowed to access the radio channel. This phase is referred to as RACH (Random Access Channel) and is set in H / 2.

In Figure 3 is the extension of a MAC frame to a subframe shown for relay operation, as defined in this invention for the H / 2 system. The MAC frame is defined by the AP and the FMT assigned on the uplink in a specific transmission capacity, which can be at any of a subframe for transmitting its own UL data to the AP and transmitting UL / DL data between FMT and RMT the FMT. The AP provides this subframe as FMT uplink SIOT being ensured by appropriate labeling of the data packets that data at this stage are sent out for the relay connection from FMT for RMT, are not interpreted by the AP as Uphnk data of FMT in the subframes in turn each stage of the H / 2 be used, but matched in one of the partial structure form

In this example, the FMT initially sends NECESSARY for organizing the data link information in the F-BCH (forwarders-BCH, a broadcast channel, generated by the FMT and is received by the RMT) Then the RMTs the further construction of the subframe in F -FCH (forwarders frame Control channel) notified the subsequent F-ACH (Forwarder Acknowledgement channel) the RMTs of success for a transfer to the later explained F-RACH is notified subsequently the FDL phase takes (Forwarder downlink) instead, in the the FMT, sends data to the addressed RMTs This may be in any sequence of LCH data packets (Long channel, packets 54 bytes) or SCH data packets (Short channel, packets to 9 bytes) happen the individual packets can thereby also to package - be summarized Zugen After ümschaltzeit for the transmitter / receiver of the FMT, can from a RMT received FMT data in the F-UL (Forwarder uplink, this is a compound RMT → FMT) Once again, any consequences of LCH and SCH emerge -Datenpaketen in the F-RACH phase RMTs, optionally send data to the FMT can, this happens in the defined in this invention subframe analogous to those already established for H / 2 mechanisms for random access following the phases of the relay connection includes the FMT to own up nk, to send data to the central station of the system using industry standard mechanisms of H / 2 are used

The organization of the subframe may be carried out either autonomously by the FMT, and died your t by the AP The FMT is a wireless H / 2 basestation The RMT is a wireless terminal (MT), as defined in accordance with H / 2 Standard

It is also possible, in the F-DL phase of the FMT also again to define a sub-frame for a cascaded relay connection Thus, a recursive structure of subframes, the depth of which corresponds to the number of partial connections (hops) yields - 9 -

The sub-frame may have a same or a different length than the frame of the AP. It appears to be appropriate, the sub-frame from the FMT periodically to generate as the AP, however, with a corresponding offset. See Figure 3 in the same cycle.

literature

[1] DE 195 35 329 AI.

[2] ETSI. Digital cellular telecommumcation; Mobile Station - Base Station System (MS-BSS) interface; General Aspects and priciples, GTS GSM 04:01. European Telecommunications Standards Institute, November 1996. EN.

[3] ETSI. Broadband Radio Access (BRAN), High Performance Radio Local Area Network (HIPERLAN) Type 1; Functwnal Speaficatwn VI.2.1, EN 300 652. European Telecommunications Standards Institute, September 1998. EN.

[4] ETSI. Digital cellular telecommumcation (Phase 2+), General Packet Radio Service (GPRS); Overall descriptwn ofthe GPRS radio interface, TR 101 350 (GSM 03.64). European Telecommunications Standards Institute, October 1998. EN.

[5] ETSI. Broadband Radio Access Networks (BRAN); HIPERLAN Type 2 Functwnal Speaficatwn Data Link Control (DLC) Layer Part 1 - Basic Data Transport Functwn, DTS / BRAN030003-1 VOλ. European Telecommunications Standards Institute, September 1999. DTS.

[6] ETSI. Broadband Radio Access Networks (BRAN); HLPERLAN Type 2 Functwnal Speaficatwn Data Link Control (DLC) Layer Part 4 - Extenswn for Home Environment, DTSIBRAN -0020004-4 VO.z. European Telecommunications Standards Institute, August 1999. DTS. - 10 -

[7] IEEE. Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications. Broadband Radio Access (BRAN); 802.11, IEEE, New York, November 1997. EN.

[8] D. Petras. Development and Performance Evaluation of A TM Funkschnittstelk .. Aachen Contributions to the mobile and telecommunications, Volume 18, Wissenschaftsverlag Mainz, Aachen., 1999