Gsm to umts inter-system handover

【0001】

[Technical field]

The present invention relates to the field of cellular telephones, in particular from cells that use radio access technology by the Global System (GSM) for mobile communications, to the Universal Mobile Phone System (UMTS) Terrestrial Radio Access Network (UTRAN). It is involved in the transmission of information from a cellular network to a mobile station regarding handover between cells using various radio access technologies, such as to cells using radio access technology.

【0002】

[Background technology]

Mobile station GSM-to-UTRAN handover / cell reselection in cellular networks, including various cellular systems such as GSM and UMTS, which use so-called wideband code division multiple access (WCDMA) and are accessed by UTRAN. From the target cellular network to the mobile station, the so-called channel, in order to be sufficiently fast, that is, to perform an appropriate and rapid handover from the current wireless access technology (RAT) GSM to the target RAT UTRAN. It is necessary to transfer various items of information, including preconfiguration parameters. For so-called hard-coded or static presets, the criteria specify preset parameters. That is, the reference gives a set of values for a predetermined number of preset parameters and defines a configuration with values for each set. Examples of preset parameters are transport block size and transport block set. It is a parameter indicating size), spreading factor, CRC and TTI (transmission time interval) values. Because the static preset parameters are specified as criteria, the mobile station usually knows each static preset parameter (that is, its value) and keeps its static configuration in memory. Can be expected. However, in addition to static presets, there are so-called dynamic configurations. These are usually information about the behavior of the target RAT, in addition to what is provided by one of the static presets. However, the dynamic communication specification can be complete on its own and on its own. That is, the dynamic communication specification can specify all of the target RAT's configuration parameters by itself, instead of supplementing the information given by the static preset, so it can completely specify the target RAT's configuration by itself. ..

【0003】

Unlike static presets, the preset parameters that make up the dynamic communication specification (whether it complements the static preset or is intended to be complete in itself). The set of must be provided to the mobile station dynamically, that is, at or near the time of the mobile station handover from GSM to UTRAN.

【0004】

Section 13.7 of TS25.331 Version 3.7.0, entitled Parameter Values for Default Radio Configurations, defines (static or hard-coded) presets and sets them up. We call it the default configuration. Section 13.7 specifies the parameter values required for each (hardcoded) preset. The UE keeps these (hardcoded) presets in memory.

【0005】

System Information Block (SIB) Type 16 defines a dynamic communication specification called a predefined configuration in Section 13.7 of TS25.331. SIB type 16 contains radio bearer, transport channel and physical channel parameters that should be kept in the memory of the UE. System information is specified to include preset identities and value tags to identify a particular dynamic communication specification, as well as to update the dynamic communication specification when needed.

【0006】

WCDMA is the most widely adopted air interface for so-called 3rd generation wireless communication systems, and GSM is the corresponding interface for so-called 2nd generation (ie digital) wireless communication systems. (The first generation system is analog.) In connection with the third generation partnership project (a joint standardization project of standardization bodies in Europe, Japan, South Korea, China and the United States), WCDMA is UTRA (Universal Terrestrial Radio Access). Called, it can be either WCDMA FDD (Frequency Division Duplex) or WCDMA TDD (Time Division Duplex).

【0007】

In UTRA, data generated at higher layers is transported over the air interface through transport channels mapped to various physical channels in the physical layer. Two types of transport channels: dedicated channels (reserved for a single user because each is identified by a particular code on a particular frequency), and common channel (common channel) ( Resources that are distributed among all users in the cell or among a group of users). There are multiple (usually 6) different common transport channel types defined in UTRA, one of which is the so-called broadcast channel. channel: BCH). BCH is used to send specific information to a UTRA network to a given cell. Associated with the BCH (which is the physical transport channel) is the logical channel, called the broadcast channel (logical channel), which is referred to as the BCCH. For clarity, the corresponding transport channel, referred to as BCH, is referred to as the broadcast channel (transport channel).

【0008】

The primary common control physical channel (primary CCPCH) is the physical channel that carries the broadcast channel (BCH). It needs to be demodulated by all mobile stations in the system. As a result, parameters related to channel coding and spreading code (for example) are inflexible because they need to be known by all terminals made since the publication of the so-called Release 99 specification. The content of signaling messages has room for flexibility unless the new message structure causes unnecessary or unpredictable behavior on mobile stations deployed within the network.

【0009】

Logical channels are mapped to physical channels at the so-called media access control (MAC) layer. A set of logical channel types is defined for the various types of data transfer services provided by the MAC layer. Each logical channel type is defined by the type of information transferred. There are two general categories. That is, a logical control channel used to transfer control information and a logical traffic channel used to transfer user information. BCCH is a logical downlink (base station to mobile station) channel used to broadcast system control information. BCCH is mapped (connected to) to BCH (Physical Channel) of the MAC layer. (It may be mapped to a so-called FACH, a forward access (physical) channel).

【0010】

It should be noted that the terms UMTS BCCH and UMTS BCH refer to the same channel in UMTS. The term BCCH is used to refer to a logical channel, but the term BCH refers to the actual transport channel carried by the primary CCPCH described in 3GPP TS 25.211, Version 3.4.0, Chapters 4-6. Used to point.

【0011】

The GSM BCCH capacity is limited and is not a suitable means of transferring additional (dynamic) preset parameters to the mobile station. Regardless of how the transfer is performed, it is beneficial to keep the power consumption of the mobile station as low as possible. Therefore, when the dynamic communication specification is transmitted on the UTRA BCCH, the dynamic communication specification is frequently repeated in the UTRA BCCH system information so that the UE does not have to keep decoding the UTRA BCCH for too long. is required. In other words, the UE should not have to wait too long for the dynamic communication specifications to reappear. On the other hand, if the UTRAN quality (coverage) is poor, or if the dynamic communication specification is not used in the network, the UE should not attempt to decrypt the UTRA BCCH. Unnecessary decoding of UTRA BCCH increases idle mode activity of the UE and thus increases power consumption.

【0012】

The criteria set forth in the specification, 3GPP 25.302, version 3.60, Chapter 7, describe a particular channel transport format combination (TFC). (This is supported by at least some mobile stations.) In addition, Vodafone (R2) that additional (dynamic) preset parameters are transferred from the cellular network (ie, the base station) to the mobile station. -002015) There is a proposal. However, the proposal does not show how fast (and also reliable) transfers can be made to obtain handover / cell reselection with acceptablely low power consumption by the mobile station. .. In addition, conventional technology reselects between RAT (Wireless Access Technology) cells, that is, the so-called ping pong (hand back and forth between one system and another) when selecting between GSM and WCDMA (UTRA), for example. It does not teach how to avoid over / cell reselection).

【0013】

What is needed is a cell operating under UTRA when handed over from a cell operating under GSM to a cell operating under UTRA (WCDMA). This is a method for quickly and surely communicating the dynamic communication specification information required by the mobile station for the operation of the mobile station.

【0014】

[Summary of invention]

Therefore, the present invention provides a mobile station and a method for the base station to which the mobile body is handovered, and a corresponding device for use by the mobile station and the base station. The method for use by a mobile station is to determine if the dynamic communication specification is being used by the base station to which the mobile is handed over, and the mobile is handed over. The above base station belongs to the first wireless communication system, and the base station that executes the handover belongs to a different wireless communication system. (The first wireless communication system is a universal mobile phone system terrestrial wireless connection (UTRA) or the like, and the different wireless communication system is a global system (GSM) wireless communication system for mobile communication or the like.) It is assumed that both base stations broadcast control signals on their respective broadcast control channels. The method for use by mobile stations is: a) the step of determining whether the signal level of the control signal broadcast by different wireless communication systems meets the criteria for reselection between predetermined systems. b) the step of receiving the control signal broadcast by the first wireless communication system, c) the step of executing the error check of the reception control signal broadcast by the first wireless communication system, and d) the first step. Including the step of decoding the control signal broadcasted by the wireless communication system of the above and reading any dynamic communication specification broadcasted by the base station of the first wireless communication system at the time of decoding. If the error check fails, the mobile station performs a step of waiting at a predetermined time interval and then repeats the method starting with the step of receiving the control signal from the first wireless communication system.

【0015】

In a further aspect of the invention, the mobile body demonstrates a step of decoding control signals broadcast by different radio communication systems, and whether the base station of the first radio communication system uses dynamic communication specifications. A control signal broadcast by the first radio communication system only if the step of reading the flag bit is performed and the flag bit indicates that the base station of the first radio communication system is using the dynamic communication specification. The mobile station that receives and decodes the above steps (a) to (d).

【0016】

When deciding whether to use the dynamic communication specifications when communicating with a mobile station, the corresponding method for being used by the base station of the first wireless communication system is that the mobile station has a different wireless communication. Handed over by the system, the mobile station assumes that the transport format combination indicator (TFCI) communicates with the base station of the first radio communication according to the protocol used (at least by the mobile), a) dynamic. The steps of transmitting to and receiving from the mobile station using the communication specification parameters, b) checking the uplink TFCI to determine if TFCI refers to the dynamic communication specification, and c) uplink. When TFCI refers to a dynamic communication specification, the step of transmitting to and continuing to receive from the mobile station using the dynamic communication specification pointed to by the uplink TFCI, and uplink TFCI pointing to the dynamic communication specification. If not, it includes a step of transmitting to and receiving from the mobile station using static presets.

【0017】

From another point of view, the present invention includes a method for use by a mobile station and a corresponding device, a) a step of receiving a broadcast control signal from the base station to which the mobile station is handed over to the mobile station. And b) read any dynamic communication specifications displayed by the broadcast control signal based on the error check of the broadcast control signal, or wait until a predetermined time to repeat step (a) described above. Including either step, the mobile station is handed over to the base station by another base station. In some application examples, the steps (a) to (b) are such that the flag bit received from the base station handing over the mobile station is set to the dynamic communication specification, and the mobile station is handed over. Executed only to indicate that it will be used in a base station.

【0018】

From this other point of view, the invention also includes a corresponding method (and corresponding device) for use by a base station, a) a mobile station indicating dynamic communication specifications or state presets used by the mobile station. The step of receiving the signal from the base station at the base station and b) the step of using the dynamic communication specification parameter or the static preset parameter at the base station depending on the signal received from the mobile station. Including.

【0019】

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to avoid complicated double cell reselection criteria based on some priority depending on the availability of dynamic communication specification parameters. In this respect, the present invention is an improvement measure superior to the content provided by the prior art.

【0020】

The concept proposed by Vodafone is that if the mobile station fails to receive the dynamic communication specification, the UTRA network will be UTRA. Mobile stations must prioritize GSM over UTRA, even if BCCH is transmitting dynamic communication specifications. On the other hand, if the dynamic communication specifications are not acquired by the mobile station, UTRA must be given priority over GSM. When this type of priority is used in cell reselection, the priority is for both GSM and UTRA to avoid moving the mobile station back and forth between wireless access technologies. Must be taken into account in the cell reselection criteria. For example, if the priorities are defined solely in the GSM specification cell reselection criteria, the priority rules in the cell reselection criteria may tend to push mobile stations towards the use of UTRA. However, since such a complicated priority cell reselection rule is not defined in the UTRA specification, the mobile station will immediately return to GSM and then move to UTRA or the like again. Instead of having these various types of precedence rules in cell reselection criteria, the present invention allows UTRA networks to use dynamic communication specifications (UTRA). BCCH also sends its dynamic communication specifications), but due to poor UTRA signal quality, or the mobile station is in GSM-only mode and does not have a dual receiver to receive both GSM and UTRA data at the same time. Therefore, we define a mechanism for recovering from the situation where those dynamic communication specifications could not be received from UTRA BCCH.

【0021】

Complex cell reconfiguration in both GSM and UTRA to make the concept work properly and to avoid ping-pong conditions between the two radio access technologies (ie, in this case between GSM and UTRA). Selection criteria (rules) are required.

【0022】

Moreover, the power consumption of the mobile station can be reduced using the present invention. Because, according to the present invention, the UE periodically searches for dynamic communication specifications based on the cell reselection metric whose signal level of the measured GSM signal is defined between UMTS and GSM (implementation). This is because it is only when it is above or below a predetermined threshold (depending on). Therefore, the network operator can control the terminal power by setting a threshold value so that the UE does not have to try to read the dynamic communication specifications when the signal quality of the UTRA network is not sufficient.

【0023】

Finally, the network is a dynamic communication specification, or (hardcoded or hard-coded, that is, depending on what kind of configuration the network supports and what services the operator wants to provide. You can choose to use either of the (static) presets.

【0024】

The above and other objects, features and advantages of the present invention will become apparent by reviewing the subsequent detailed description presented in connection with the accompanying drawings.

【0025】

[Best mode for carrying out the invention]

The present invention is a method and protocol for use in the case of mobile station handover from a cell using GSM to a cell using UTRA. It prepares the mobile station to acquire the dynamic communication specification parameters used in the operation in the UTRA cell, if feasible. Dynamic communication specification parameters are static preset parameters (sets that are known in advance to any mobile that can operate in a UTRA cell because each set describes a particular configuration and the set is specified by a reference. In contrast to (organized in), it must be communicated to the mobile station as it is not known a priori to the mobile station. Dynamic communication specification parameters may be added to static configuration parameters to fully identify the configuration, or may be used only with dynamic communication specification parameters. Examples of preset parameters include parameters that indicate the transport block size, transport block set size, diffusion coefficient, CRC in use, and TTI (Transmission Time Interval) values. The preset parameter values are transmitted to the mobile station according to one of three methods, as described below.

【0026】

Some mobile stations have a function to read the dynamic communication specification parameters, while others do not, and it is necessary to determine which case the base station to which the mobile station is handed over is. The present invention includes the following methods, in which a mobile station experiencing a GSM-to-UTRA handover (at least if the mobile station has the ability to read dynamic communication specification parameters). From the base station (node B) to which the mobile station is handed over, a dynamic configuration for use in the UTRA cell (a set of parameters and their values, or a parameter with an indicator of which set to use). Either the value of or a set of values) can be obtained. Furthermore, this method also includes a method of executing a step followed by a UTRA base station (so-called node B) in the case of a GSM to UTRA handover, and the UTRA base station causes the mobile station to set its dynamic communication specification parameters. Determine if it has been read. (The mobile station is not reading the dynamic communication specification parameters either because it does not have the ability to read them, or because the signal conditions are poor and it cannot be read).

【0027】

For example, a network can have a cell that operates according to GSM and another cell that follows UTRA, and the base station (node B) for cells operating according to UTRA has a given static setting (ie). , Pre-configured), and in addition, it can operate according to dynamically defined parameters instead of the predefined parameters. Which of the given (static) presets should be used for the handed over mobile phone (all of which presets are retained in the mobile station's storage for the purposes of this example). To indicate (assumed), the UTRA base station can use a default channel preset indicator with eight possible values. (That is, eight values for a single (hardcoded) preset indicator, each of which indicates a separate preset as defined by the criteria). Next, for mobile stations (hard handover, soft handover, or even softer handover) that are handed over from the GSM channel to the UTRA channel, the network (via either the GSM base station or the UTA base station). However, the mobile station must be informed of the value of the preset indicator. To do this would require transmitting 3 bits to the mobile station, which is performed by the present invention using a dedicated handover command message (more specifically, a handover command message to UTRAN). To. In addition, the network can define four additional dynamic communication specification parameter values. According to the present invention, these dynamic communication specification parameter values are also UMTS. Sent to the mobile station on BCCH (with a 3-bit indicator of static preset parameters). In this example, the network (and, more specifically, subject node B) is moving because it broadcasts only certain additional dynamic communication specification parameters used by the network, rather than a set of dynamic communication specification parameters. The station does not need to get a set of dynamic communication specification parameters, nor does it need to get an indicator to indicate which dynamic communication specification set to use, an additional set used by node B instead. You only need to get the configuration parameters.

【0028】

Mobile stations typically keep all (hard-coded) preset copies in storage. As a result, when a GSM-to-UTRAN handover command message is issued by a GSM network, the GSM network does not need to send the actual parameters used to initiate a dedicated channel connection in UTRAN to the mobile station. .. Instead, as in the previous example, the GSM network can reference specific (static) presets that use certain parameter values (ie, preset indicators). (The GSM to UTRAN handover command is sent to the mobile phone over the GSM network. However, the UTRAN handover message is first sent from the UTRAN network to the GSM network and then to the mobile phone. Will be). On the other hand, only the dynamic communication specification (set of parameters), or instead, the dynamic communication specification parameter used by the cell to which the mobile is handed over is UTRAN. Broadcast on the BCCH channel, the dynamic communication specification parameters may, of course, vary from network to network, that is, from public land mobile network (PLMN) (but different nodes within a PLMN). Same for B). Therefore, UTRAN broadcasts the actual preset parameters for each dynamic communication specification (that is, for each different set of dynamic communication specification parameters) along with the indicator, or instead, the actual used by UTRA. Dynamic communication specification parameters (their identities and values) must be broadcast. Obviously, if the UTRAN cell broadcasts a set of dynamic communication specification parameters and an indicator of which set will be used, the (hardcoded) preset indicator and the dynamic communication specification indicator are distinguishable. There must be.

【0029】

There can be multiple broadcasts of dynamic communication specifications in UTRAN BCCH, and each dynamic communication specification usually represents different services and different data rates. Each dynamic communication specification (as well as each preset) also contains multiple parameters for both downlink and uplink. When a handover is commanded (by a GSM base station), only one preset is referenced in the command. The referenced preset defines all the parameters required for both uplink and downlink.

【0030】

The present invention includes two parts. That is, firstly, it is used in two alternative ways for the mobile station to know if the UTRAN cell uses the dynamic communication specification, and if the UTRAN cell uses the dynamic communication specification. One way to receive information that identifies a dynamic communication specification, secondly, a protocol followed by a UTRAN cell that uses the dynamic communication specification when communicating with a mobile station. Includes a way to communicate with the mobile to see if it is ready to use the specification.

【0031】

With reference to FIG. 1 of the first embodiment of the method by which the mobile station knows whether the dynamic communication specification parameter is used by the UTRAN cell to which the mobile station is handed over, the UTRAN cell communicates dynamically. In a first embodiment of the method according to the invention for allowing a mobile station to determine if a specification parameter is being used, in determination step 11, the mobile station sets a predetermined (specified) reference for the GSM signal level. Determine if it meets. That is, it determines whether the signal level (or signal quality) of the measured GSM signal is above a predetermined threshold based on the metrics for cell reselection defined between UMTS and GSM. The signal level is provided, for example, by the Received Signal Strength Indicator (RSSI). (If the received signal strength is not sufficient, that is, if the prescribed criteria are not met, it is useless to try to read the dynamic communication specifications, so the terminal does not have to try to read the dynamic communication specifications). The threshold used for inter-system reselection is a downlink channel, such as a broadcast channel available to mobile stations, especially if the handover / cell reselection is from a GSM cell to a UTRA cell. It is transmitted by BCCH. If the GSM signal level meets a predetermined criterion, in the next step 12, the mobile station repeatedly receives and attempts to decode UMTS BCCH to determine if the dynamic communication specification is used. After receiving the UMTS BCCH, in the next determination step 13, the mobile station determines whether the received signal passes the CRC check. If so, in the next step 15, the mobile station reads the dynamic communication specifications from UMTS BCCH. If a dynamic communication specification exists, the mobile station determines whether the UTRA cell uses the dynamic communication specification, and if it uses the dynamic communication specification, what kind of dynamic communication specification does the mobile station have? To judge. If the received GSM UMTS signal does not pass the CRC check, in step 14, the mobile station waits for the interval T_attempt between UMTS BCCH receptions to elapse before receiving UMTS BCCH again in step 12. Try. Time interval T_attempt to UMTS to mobile station Used to avoid having attempts to continuously decrypt BCCH (such attempts interfere with paging reception in GSM, which also causes increased IDLE mode activity. Will).

【0032】

In such an embodiment, in order to obtain the dynamic communication specification parameters used by node B (or instead, a set of dynamic communication specification parameters and an indicator of which set is used) (GSM). UTM S BCCH reception and decryption (performed before the actual handover from to UTRA) is performed when the mover is in IDLE mode (during paging reception).

【0033】

A second embodiment of how the mobile station knows whether the dynamic communication specification parameter is used by the UTRAN cell to which the mobile station is handed over. Next, with reference to FIG. 2, the dynamic communication specification. In a second embodiment of the method of the invention for allowing the mobile station to determine whether the parameter is used by the UTRA node B to which the mobile station is handed over by the GSM base station, the GSM base station , Sends a flag bit on the GSM BCCH indicating whether node B uses the dynamic communication specification, and in the first step 20 (by the mobile), the mobile station receives the GSM BCCH and reads the flag bit. Decrypt it so that. In the next step 20a, the mobile station determines if the flag bit indicates that the dynamic communication specification is being used by the UTRA cell, and the flag bit indicates that the dynamic communication specification is being used. GSM, if indicated Interval between BCCH reads As in the method described above, which relies on the use of T_attempt, the mobile station acquires the dynamic communication specification. In this way, in determination step 21, the mobile station determines whether the GSM signal level meets a predetermined criterion. That is, the mobile station determines whether the signal level (or signal quality) of the measured GSM signal is above a predetermined threshold. The threshold is defined based on the metric for cell reselection established between UMTS and GSM. If the GSM signal level meets a predetermined criterion, in the next step 22, the mobile station periodically receives the GSM BCCH and attempts to decode it. After receiving the GSM BCCH, in the next determination step 23, the mobile station determines whether the received signal passes the CRC check. If the received signal passes the CRC check, in the next step 25, the mobile station reads the dynamic communication specification from the GSM BCCH (by displaying the flag bit, it is known that the dynamic communication specification exists). Then know which dynamic communication specification is used by the UTRA cell. Received GSM If the BCCH signal does not pass the CRC check, in step 24 the mobile station waits for the interval T_attempt between GSM BCCH receptions to elapse and then attempts step 22 to receive GSM BCCH again.

【0034】

The reception and decryption of the UTMS BCCH performed by the method shown in Figure 2 (performed before the actual handover from GSM to UTRA) is as in the flag bit independent method shown in Figure 1. Executed while the mover is in IDLE mode (during paging reception). In the method shown in Figure 2, the mobile station does not need to decode the UTMS BCCH transmission if the flag bit provided by the GSM base station indicates that the dynamic communication specification is not used by node B.

【0035】

How to make a UTRA base station (ie node B) decide whether to use dynamic communication specification parameters when communicating with a mobile that is experiencing handover from a GSM base station. In UTRA node B, which uses one dynamic communication specification or another dynamic communication specification from time to time, when node B communicates with a mobile station that is handovered from a GSM cell to node B, which node B is When deciding whether to use a dynamic communication specification, the method that Node B should follow depends on which dynamic communication specification Node B generally uses, and there are two possible courses. The first decision step 31 for node B to proceed to one of the courses 32 and 33 is shown as the beginning. Therefore, the method is UMTS. It relies on information about dynamic communication specifications broadcast via BCCH. If node B is currently using the dynamic communication specification, when communicating with a mobile that is handed over from the GSM cell to node B based on whether the mobile phone can read the dynamic communication specification. You must decide whether to use dynamic communication specifications or (hardcoded) presets. (As mentioned above, whether the mobile station does not have the ability to read the dynamic communication specifications, or whether external factors such as factors that cause bad reception prevent the mobile station from reading the dynamic communication specifications. Either way, the mobile station may not be able to read the dynamic communication specifications). According to the present invention, when node B is using the dynamic communication specification parameter, in order to determine whether the mobile has detected the dynamic communication specification parameter, in determination step 34, node B is referred to as a so-called transformer. Code in the Transport Format Comination Indicator (TFCI) Examine the uplink transmission to see if word) indicates a dynamic communication specification and, depending on the outcome of the decision, proceed to one of two possible courses 35, 36. Such codewords indicate a particular transport format combination set suitable for the source data transfer rate, as described by TS25.212, Sections 4.2.7 and 4.3, and are associated with dynamic communication specifications. The codeword used is different from the codeword used in connection with static presetting.

【0036】

The DPCCH (Dedicated Physical Control Channel) structure must be the same for both the (hardcoded) preset and the dynamic communication specifications, and the SF (Diffusion Coefficient) is uplink in all cases. Is fixed at 256. If node B determines that the uplink TFCI does not refer to the dynamic communication specification, then in step 35, node B continues to communicate with the mobile station using the dynamic communication specification. Otherwise, in the next step 36, Node B uses the corresponding static preset downlink parameters (for each different service, for example, for different data transfer rates, etc., with a few individual pre-configurations). There is a configuration, so the network and terminal can perform a one-to-one mapping from the dynamic communication specification to the preset (based on the data rate and spread coefficient), so the network first transfers data to the downlink. If you use the dynamic communication specification for speed C, it uses the presets that correspond to the same data rate C).

【0037】

The dynamic communication specification pointed to by TFCI does not have to be the same dynamic communication specification used by node B in the downlink (and usually not the same dynamic communication specification). Uplink and downlink configurations (preconfigured or dynamic communication specifications) are often different. For example, the uplink data transfer rate is often different from the downlink data transfer rate. However, if the uplink TFCI refers to the dynamic communication specification, the network knows that the mobile has received dynamic configuration parameters from the UTRA BCCH, so the network continues to use the dynamic communication specification. be able to. If the terminal exhibits a dynamic communication specification on its uplink, it is taken for granted that the mobile receives all (or at least all related) dynamic communication specification parameters.

【0038】

When node B first communicates with the mobile station (in step 32), the node (according to step 31) before making sure that the mobile station uses the dynamic communication specifications used by node B. B should use as a dynamic communication specification a communication specification with the same parameters (such as diffusion coefficient as well as DPCCH structure) as the preset (ie, dynamic for both downlink and uplink). There must be a one-to-one mapping between the communication specifications and the presets). Node B also ensures that communication control parameters such as power control are handled without the question of whether the mobile station can read the dynamic communication specifications. If the network chooses to use a particular dynamic communication specification and determines that the mobile station is using a (hard-coded) preset, the network will be subject to the dynamic communication specification in accordance with the present invention. The downlink DPDCH (Dedicated Physical Data Channel) portion specified for this must be replaced with the DPDCH specified for (hardcoded) preconfiguration. As mentioned above, the decision can be made by examining the set of TFCI codewords that the mobile station sends to node B. If a TFCI codeword for (hard-coded) presetting is detected, the downlink DPDCH must be adjusted as described (assuming the DPCCH parameters are the same for both presets). Otherwise, the DPCCH parameters need to be adjusted in the same way, that is, the dynamic communication specification DPCCH value must be replaced by the static preset DPCCH value used by the mobile. (Do not).

【0039】

Next, referring to Figure 4, the frame structure for the downlink dedicated physical channel (DPCH) radio frame according to TS25.211 version 3.5.0, Section 5.3.2 is shown as containing 15 slots. Each slot has the number of bits in the DPDCH N_data1, Number of bits in DPCCH N_TPC+ N_TFCI,, Number of bits from DPDCH N_data2, And finally the number of bits from DPCCH N_piloConsists of. Where the number of bits N_TPCIndicates TCP, the number of bits N_TFCIIndicates TFCI. One slot is 10x2^kIt consists of 2560 chips corresponding to bits, where k = 0, ..., ... 7 depends on the slot format. Several different slot formats are shown in Table 1 below. Table 1 is a partial copy of Table 11 in TS25.211, version 3.5.0, Section 5.3.2 [0040].

[table 1]<img file="JP2004534412A_D0001.tif" /> 【0041】

Number of TPC bits N_TPCIs either 2, 4, or 8, and as shown in Table 2, all bits are (respectively) 0, depending on whether the transmitter power control command is 0 or 1. Or 1. Table 2 is a copy of Table 13 in TS25.211, version 3.5.0, Section 5.3.2 [0042].

[Table 2]<img file="JP2004534412A_D0002.tif" /> 【0043】

Therefore, the mobile station can determine whether the transmitter power control is 1 or 0, even if the mobile station receives only one of the TCP bits.

【0044】

In the downlink direction, even if the same diffusion coefficient used for presetting is used for the dynamic communication specification (TS25.211 partially duplicated as Table 1, version 3.5.0, Because there is a slot format greater than 1 defined for the specified diffusion coefficient (according to Table 11 in Section 5.3.2), the slot format for dynamic communication specifications is a slot for the corresponding preset. It may still be different from the contents of the format. Therefore, the DPCCH structure of the dynamic communication specification may still differ from the structure for the corresponding preset. This is because, for example, the position of the power control command slot (in the frame) is always fixed in this way and can be detected whenever the diffusion factor is known. (The number of pilot symbols may vary from slot format to slot format, even if the diffusion coefficients remain the same, but if the diffusion coefficients remain the same, the power control symbol N (indicating a power control command)_TPCAt least some of the bits are always in the same position in the slot, so power control commands can always be detected as long as the spread coefficients are the same. This is because detecting multiple TPC bits is always preferable for even greater reliability, but (depending on whether the power control command is 1 or zero, all TPC bits are either 1 or zero. This is because only one TPC bit must be determined to determine the power control command. Detecting power control commands is essential to maintain reasonable system performance). If the number of pilot bits in the DPCCH field for dynamic communication specifications and presets is not the same, there is some degradation in the channel estimation process (for example, the dynamic communication specification slot format has 8 pilot symbols). The preset slot format may have only 4 pilot symbols. These known pilot symbols are used to estimate the channel, so the difference in the number of pilot signals is the estimation process. Causes deterioration in).

【0045】

When a mobile station experiences a GSM-to-UTRAN handover, it is already using a particular service, and thus a particular data transfer rate when communicating over the GSM. The service being used must be maintained during the handover. Since the mobile station knows its current service and data transfer rate within the GSM prior to handover, it can determine which (UTRAN) preset matches its data transfer rate within the GSM. The mover must choose both a matching uplink configuration and a downlink configuration based on the current uplink data transfer rate and downlink data transfer rate. Once the mover receives a handover command from the GSM side to switch from GSM to UTRAN, the handover command contains an index pointing to either the dynamic communication specification or the (hardcoded) preset. Therefore, mobile stations know to use either (hardcoded) preset parameters or dynamic communication specification parameters.

【0046】

If the mobile station is able to read the relevant information block in UMTS BCCH before receiving the handover command, the mobile station will have any dynamic communication specification parameters required (synchronous). They will be used for dedicated channel transmission after the handover procedure is completed (including etc.). If the mobile station is unable to acquire (read) the dynamic communication specification parameters prior to the handover, the mobile station will be stored in the (hardcoded) preset parameters and (mobile station memory). Use those values automatically. Because the uplink data transfer rate and the downlink data transfer rate are different, the mobile station presets both the uplink data transfer rate and the downlink data transfer rate to match the transfer rate used by the mobile station in the GSM. Must be used.

【0047】

Aspects of a mobile station receiver that reads dynamic communication specification parameters Next, referring to FIG. 5, the main configurations of the mobile station 50 used in carrying out the method of the present invention shown in FIGS. 1 and 2. The elements are shown. The components that realize the present invention are collectively shown as the device 51. Mobile station 50 includes: Antenna 52 that enables signal reception. Broadcast control signals from UMTS and GSM base stations (ie, GSM BCCH, and UMTS Receiver (RX) module 53 that receives signals on a variety of channels, including BCCH signals). Decoder 54 that decodes the received signal. And controller / timer 55. The signal level (eg, indicated by RSSI) is determined from the signal received by receiver 53. The CRC check is performed by the decoder 54. A signal level (by controller / timer 55), for example as indicated by RSSI, is used to determine if the GSM signal level meets certain criteria for continuing to read the dynamic communication specifications. Recall that) CRC check and signal level (RSSI) are both given to controller / timer module 55. The controller / timer module 55 controls the receiving module to receive the presets as described above as various embodiments of the method of the invention shown in FIGS. 1 and 2. It is the controller / timer module 55 that implements the method of the invention shown in FIG. Based on the logic shown in FIGS. 1 and 2, the controller / timer 55 provides the decoder control signal to the decoder 54 and receives the UMTS. Extract (read) dynamic communication specifications from BCCH. In addition (or), the controller / timer 55 receives the UMTS BCCH again (after the CRC check that failed and after the controller / timer waits for a period of time T_attempt from the last failed CRC check). Therefore, a receiver control signal is given to the receiver 53. Corresponding to the embodiment shown in FIG. 2, the decoder 54 provides a flag bit extracted from the received GSM BCCH signal and the controller / timer determines if the dynamic communication specification is used. The flag bit is used for this purpose. The assignment of functions between the receiver 53 and the decoder 54 shown in FIG. 5 is optional in several respects and the present invention is made by the receiver / decoder module 56 combined as shown in FIG. It is more commonly represented.

【0048】

Next, with reference to FIG. 6, the main components of the base station 60 used in carrying out the method of the present invention shown in FIG. 3 are shown. The components that realize the present invention are collectively shown as the device 61. Device 61 includes: Antenna 52 that transmits signals to multiple mobile stations and receives signals from multiple mobile stations. Transceiver (TRX) module 63 for providing the signal transmitted to the mobile station as a transmitter signal and receiving the (RAT) signal from the mobile station. Here, the transmitter signal is a broadcast control signal (UMTS). BCCH) and other signals are also included, and the received signal includes an uplink TFCI (which may indicate dynamic communication specifications). A decoder 64 that decodes any received signal and thus provides the uplink TFCI contained in any received signal. And control device 65. Based on the steps shown in FIG. 3, the controller is equipped with an uplink TFCI from a mobile station by a decoder, which determines how to communicate with the mobile station based on the uplink TFCI. Note that the decision whether a base station (node B) uses any of the dynamic communication specifications is usually made by the radio network controller (RNC) that controls the base station, not by the base station. I want to be. As in the case of the mobile station receiver / decoder shown in FIG. 5, the assignment of functions between the transceiver 63 and the decoder 64 shown in FIG. 6 is also optional in some respects, and the present invention is in this invention. , Represented more generally by the transceiver / decoder module 66 combined as shown in FIG.

【0049】

Description Decoding of UMTS BCCH signals to obtain dynamic communication specification parameters can be performed using any variety of known methods. The implementation of CRC (that is, how many bits are used for CRC) is a criterion specific issue. RSSI can be determined by detecting the received RF signal level. The signal level is then converted to digital form by the A / D converter and given to the controller / timer module (Figure 4). UMTS The reception of BCCH transmissions is preferably performed between paging receptions as described above. It is assumed that the controller / timer module knows the paging reception timing interval information, and the paging reception timing interval information depends on the telecommunications standard in use. The controller / timer module uses paging reception information and timer interval T_attempt to control the receiver circuit of the device. In other words, the controller / timer module controls the receiving module so that the receiving module repeatedly attempts to read the dynamic communication specification parameters, and during each trial, the T_attempt set by the criteria used. Wait at time intervals. Needless to say, new attempts will only be made if previous attempts have failed.

【0050】

The timer interval T_attempt and optional bits will preferably be defined by the criteria. (These timer interval T_attempt and optional bits are provided on the GSM BCCH to indicate whether node B to which the mobile station is handed over uses the dynamic communication specification.) Timer interval T_attempt The requirements for decoding the dynamic communication specification parameters with respect to (either the value of T_attempt or how the value of T_attempt is transmitted) must also be stated in the reference.

【0051】

As mentioned above, it is generally beneficial to keep the power consumption of mobile stations as low as possible. Therefore, when dynamic communication specifications are transmitted over UTRA BCCH, these dynamic communication specifications are frequent enough in the UTRA BCCH system information so that the UE does not have to keep decoding the UTRA BCCH for too long. It is beneficial to be repeated in. In other words, the UE should not have to wait too long for the dynamic communication specification to reappear. On the other hand, if the UTRAN quality (coverage) is poor, or if the dynamic communication specifications are not used within the network, the UE should not attempt to decrypt the UTRA BCCH. Unnecessary decoding of UTRA BCCH increases idle mode activity of the UE and thus increases power consumption.

【0052】

Scope of the Invention It should be understood that the configurations described above merely illustrate application examples of the principles of the present invention. In particular, the present invention relates to a GSM cell to a UTRA cell in terms of how to determine whether a UTRA cell passing a mobile station uses dynamic communication specification parameters when communicating with a mobile body. It is useful not only for the handover of, but also for the handover from one UTRA cell to another UTRA cell, that is, the internal UTRA cell handover. Further, the present invention is not only a handover from a GSM base station to UTRA node B, but also any second different suitable type of radio communication system from any other suitable first radio communication system base station. It is clear that it also includes a handing off to. A number of variants and alternative configurations may be devised by those skilled in the art without departing from the spirit and scope of the invention, and the appended claims are intended to cover such variants and configurations.

[Simple explanation of drawings]

[Figure 1]

FIG. 5 is a flowchart of the first method according to the invention for allowing a mobile station to determine whether the dynamic communication specification is being used by the UTRA cell to which the mobile station is handed over by the GSM cell.

[Figure 2]

A second method (flow chart) according to the invention for allowing the mobile station to determine whether the dynamic communication specification is being used by the UTRA cell to which the mobile station is handed over by the GSM cell. Method is basically the first method with additional preface steps.) [Fig. 3]

A book that allows UTRA Node B to decide whether to use dynamic communication specification parameters or (hardcoded) preset parameters when communicating with a mobile station that is experiencing handover from a GSM cell. It is a flowchart of the method by invention.

[Fig. 4]

It is a schematic diagram which illustrates the structure of the physical channel (DPCH) radio frame for exclusive use of a downlink.

[Fig. 5]

FIG. 6 is a schematic / block diagram of a device (part of a mobile station) according to the present invention for receiving dynamic communication specification parameters from a base station by any of the methods illustrated in FIGS. 1 and 2.

[Fig. 6]

FIG. 3 is a schematic / block diagram of a device according to the invention that serves as part of a base station for determining how to communicate with a mobile station by the method illustrated in FIG.