UA73813C2 - Method (variants) and device for transmitter reinitialization in a wireless communication system - Google Patents

Abstract

A method and apparatus for transmitter re-initialization in a wireless communication system (10). When the communication link between a mobile station (38) and a base station (32) is in trouble, the mobile station and the infrastructure prearrange potential rescue base stations (34). The mobile station (38) disables the transmitter during the rescue process. On recovery, the transmit power level of the transmitter is incremented for transmission of the pilot strength measurement message until a hand-off direction message is received. The transmit power level is incremented to a maximum value.

Description

Description of the invention

The invention relates to wireless communication for voice and data, in particular, new improved methods and 2 devices for restoring a communication session in a wireless communication system.

A wireless communication system usually includes a set of base stations (BS), each of which is associated with a cell or sector and maintains communication with many mobile stations (MS). BSs operate under the control of the BS controller (KBS). When the MS moves in the system, the quality of the signals received by it from the BS changes. When the communication channel between the BS and a certain MS deteriorates, it is possible to prevent the loss of communication by establishing communication with 70 at least one other BS. The communication transfer process initiates the establishment of such an alternative communication channel. During communication transmission, the infrastructure performs coordination between different BSs and MSs. However, often the signal quality degrades too quickly for matching.

Therefore, there is a need for a method and device for restoring a communication session under various conditions. In addition, there is a need for a reliable way to restore a communication session in a wireless communication system. 19 The described embodiments relate to a new improved method of restoring broken communication sessions in a wireless communication system. According to one aspect in a wireless communication system having an aggregate

BSs, each of which has a neighbor group including neighboring BSs, each of which has a default channel, the method includes transmitting information about the default channel to the MS; detection of the appearance of the initiator of the restoration of the communication session; and instructing all BSs of the neighboring group to transmit on the corresponding channels by default.

According to one aspect, the wireless device includes an antenna; processor connected to the antenna; the transmission circuit connected to the antenna and the processor, the receiving circuit connected to the antenna and the processor; a first set of computer instructions executed by the computer to receive the BS neighbor list, which includes a default channel assignment for each neighbor; a second set of computer instructions executed by the computer to identify the initiator of the session reestablishment communication and switching off in response from the transmission circuit; and a third set of instructions for the computer, which are executed by the computer to perform Ge) communication transmission together with at least one neighboring BS.

According to another aspect, the wireless device includes transmission circuitry; a recovery correction node configured to operate after the recovery operation to generate predetermined power control instructions; and a power correction node connected to the recovery correction node and the transmission node and configured to operatively correct the transmission node according to the power control instructions. "--

According to yet another aspect, a computer program stored in a computer-readable medium and containing instructions for the computer and including a first set of instructions for operatively identifying a special event; the second set of instructions for the computer, designed to quickly stop the resumption of the communication session during a special event; and a third set of instructions for the computer designed to quickly notify the wireless system of a special event. -

Another aspect provides in the wireless communication system a method of restoring the communication session, which includes the transmission of a message about the measurement of the pilot signal strength at the first level of transmission power; maintaining a predetermined time delay; and transmitting a pilot signal strength measurement message at a second transmission power level higher than the first transmission power level. C 70 A wireless device that includes an antenna, a processor connected to the antenna, a transmission circuit connected to the antenna and the processor; and the first set of instructions for the computer to be executed by the processor for

From" incrementing the pilot signal strength measurement message during the resumption of the communication session.

In the drawings:

Fig. 1 is a block diagram of a wireless communication system according to one of the embodiments,

Fig. 2 is a block diagram of a part of the wireless communication system of Fig. 1 according to one of the embodiments, and Fig. 3 is a timing diagram illustrating the signal quality of two BSs in the wireless communication system of Fig. 2 according to one of incarnations

Fig. 4 is a block diagram of a part of the wireless communication system of Fig. 1 during recovery according to one of the embodiments, because Fig. 5 is a timing diagram illustrating the signal quality of two BSs in the wireless communication system according to - 20 one from incarnations

Fig. bA, 68 - scheme of operations of the method of restoring the communication session in the BS according to one of the embodiments, c» Fig. 7A, 7B - scheme of operations of the method of restoring the communication session in the MS according to one of the embodiments,

Fig. 8 is a block diagram of the architecture of the levels of the system of Fig. 1 according to one of the embodiments,

Fig. 9 is a timing diagram illustrating the operation of restoring a communication session in the system of Fig. 1 according to one of 52 embodiments,

GF) Fig. 10 is a time diagram illustrating the initialization of the transmission power level in the MS after the restoration of the communication session according to one of the embodiments of the invention, o Fig. 11 is a block diagram of the MS in the wireless communication system according to one of the embodiments ,

Fig. 12 is a time diagram illustrating the re-initialization of the transmission power level in the MS after the resumption of the communication session according to one of the embodiments,

Fig. 13 - scheme of operations of re-initialization of the level of transmission power in the MS after the restoration of the communication session according to one of the embodiments.

In one of the embodiments, the method of restoring a communication session in a wireless communication system provides the MS, which is threatened with the loss of a communication channel, with information about available neighboring cells and/or sectors suitable for reestablishing a communication session. Each of the BSs suitable for reestablishing a communication session has a default direct channel for reestablishing a communication session, identified by a predetermined code. In another embodiment, each neighboring BS is assigned more than one direct channel by default to restore the communication session and the MS uses a hash function with IM5I (International MS Identification), TIM5I (Temporary International MS Identification), EZM (Electronic Serial Number), System Time or their combination to determine the channels for receiving signals from the restoring BS. After that, the MS can use this channel to receive signals from this BOS. The MS can be instructed by service messages to combine power control subchannels from several neighboring recovery BSs when the MS accesses this BS. It can also be triggered if the MS enters the BS service area while in a passive state, i.e. without 70 continuous communication channels, by information channel messages initiating a communication session, or after a communication handover with a change in the active group of the MO.

Fig. 1 illustrates a wireless communication system 10, which has a number of cells 12, 14, 16, 18, 20, 22, 24, which have communication with the KES through an ether interface. Each of these cells has a neighbor group, which consists of cells neighboring geographically or by communication. For example, the neighbor group of cell 18 contains cells 12, 14, 75 16, 20, 22, 24. In extended spectrum systems with parallel access and code compression of channels (PDKU-SOMA), defined by the TIA/EIA/L5-95 standard ("Standard compatibility of mobile and base stations in cellular systems of two-way communication of the extended spectrum ") or TIA/EIA/L5Z-2000 ("Standard for sat?2000 extended spectrum systems"), extended spectrum signals occupy one common frequency band and each signal has its own pseudo-noise (PS) sequence. The operation of PDKU systems is described in US patents 4,901,307 and 5,103,459, which are incorporated herein by reference. Thus, several users simultaneously transmit messages in a common frequency band.

Fig. 2 illustrates a part of the system of Fig. 1, including BS1 32 in cell 18, which has communication with MS 38. The other two

BS2 34 and BSZ 36 are located in cells 16, 24, respectively. The ether radio interface creates an environment for

Direct communication channel (PC) from BS1 32 to MS 38, and for the Return channel (RC) from MS 38 to BS1 32. MO 38 can move a lot in system 10 and therefore the quality of signals between BST 32 and MS 38 can deteriorate . To start a communication session, MS 38 performs transmissions in the access channel. BS132, BS2 34 and BSZ 3b send in the call channel i) destination messages that identify the Walsh code index for each BOS.

Usually, the quality of the signal is measured as the signal/noise ratio (SNR), which can be represented as the ratio of the energy of the pilot signal code element to the total received energy density (E cLo). , received by MS 38. The quality of the signal from BS2 34 begins to increase at the moment o and continues to rise above the threshold level T AOO until the moment it Threshold level T AOO 007 gives the reference quality of the signal, above which the MS 38 receives an instruction to inform the BS about the need to add BS so to Active group (AG) of MS 38, which consists of BSs that have active two-way communication with MS 38. AG is usually formed from BSs belonging to Candidate Group (CG). CG includes BSs that are candidates for me)

35 Establishing an active connection with the MO 38. The CG is usually formed from BSs belonging to the Neighbor Group (NG). uh-

When the quality of the signal from BS2 34 increases, the quality of the signal from BS1 32 decreases. An increase in the energy level of signals from BS2 34 contributes to the deterioration of signals from BS1 32, since the quality of signals from a certain BS is determined by comparing the energy of signals from this BS with the energy of all received signals. At the moment and; measured in

MS 38 signal energy from BS2 34 exceeds T OR. This indicates MS 38 on the need for appropriate actions, that is, "initiating the transmission of communication." At time 2, MS 38 transmits to BS1 32 and KBS 26 a message about measuring the strength of the pilot signal (PVSP), which contains measurement information for BS1 32 and BS2 34. At time 3, KBS 26 establishes a communication channel from KBS 26 to BS2 34 and BS 38. KBS 26 has a selector. KBS 26 establishes a communication channel;" to form an "infrastructure" communication network between BS1 32, BS2 34 and KBS 26 for MO 38. At the moment, BSI1 32 sends a message about the direction of communication transmission (PNP), which contains information identifying BSI1 32 and

BS2 Za and their corresponding code indices for direct channels from these BSs. This information allows MS Z8 to receive and demodulate signals from BST1 32 and BS2 34. At time 5, MS 38 receives PNP from BST1 32 and begins to demodulate signals from BS2 34 in addition to signals from BS1 32. In this example, in the transmission of only two BSs participate in the connection, but in fact, any number of BSs with AG MS 38 can participate in this process. When MS 38 accepts

Go! from several BS with AG signals containing symbols, it can combine these signals to obtain a stronger 5p signal. The combining process is called "soft combining" of the direct channel, and it is usually performed with - maintaining the optimal ratio, that is, with weighting based on the quality of the signal. At time 5 4) MS 38 sends a confirmation of reception of the PNP received from BS1 32, or a message on the completion of the communication transfer (PTP), which indicates a successful completion.

A situation may arise when the signal quality from BS2 34 increases too quickly. In this case, the strength of the signal from BS2 34 relative to the strength of the signal from BS1 32 contributes to a decrease in the quality of the signal from BS1 32. The communication of MS 38 with the infrastructure is delayed until receiving the information necessary to perform the communication transfer, for example,

F) shift of the PID required for identification of BS2 34 or the communication channel of BS2 34 with MS 38. ka In the typical process of communication transfer of PDKU when the MS moves from the service area of one BS to the service area of another BS, the transfer of communication avoids the loss of communication yakuza With one type of communication transmission, namely with soft communication transmission, the MS simultaneously supports communication with two or more BSs. Current location

The MS can be considered as the source cell, and the next cell to which the MS goes as the target cell. The MS uses a "hacke" type receiver to demodulate multiple signals received in a direct channel from several BSs. These two signals are combined and give a composite signal of increased quality. Each BS participating in the soft transmission of communication separately demodulates the received signals and sends the demodulated and decoded 65 information to the CBS. The KBS selector chooses the best staff among many accepted. Depending on the conditions and requirements of the system, other types of communication transmission may be used.

When transmitting communication using the MS (PZDM), the MS measures the quality of pilot signals of the direct channel from several

BOSS. This information is sent to the originating BS. Signal qualities are compared with different thresholds to decide whether to add BS to AG. If the quality of this pilot signal exceeds the threshold AND OR

When a pilot is detected, this pilot signal is added to the AG. In another embodiment, the pilot signal may first be added to the CG and then to the AG. Thus, the threshold allows changing the BS status from one group to another.

Reestablishment of the communication session provides the MS with information in advance if negotiation of the communication transfer is not possible. The restoration of the communication session is triggered by various situations. Under normal conditions, the MS and BS use initiators to determine proper operations. For example, the MS of the system 10 uses 7/o Visa thresholds to make decisions about the information that must be transmitted back to the BS. One of the thresholds, already mentioned above T AOS, indicates the quality of the signal for adding BS to AG. When the MS receives a signal that the measurement exceeds T AYU, it transfers the BS to the CG, searches for this BS more often and reports these conditions to the system through its AG. Another threshold T OKOR determines the level of signal quality below which the BS is removed from

AG. When the MS receives a signal that the measurement is below T OCOR for a time longer than T OCOR, the 7/5 MS reports these conditions to the system through its AG. In each case, BS AG transmits this information to CBS.

To restore the communication session, the BS searches for various possible initiators in the AG. The first type of initiator of the restoration of the communication session is the situation when the signal quality of the direct channel does not reach a threshold level for a time exceeding another threshold. This type of initiator includes a situation where the BS receives continuous power control (CP) requests from the MS to increase the transmission level. Often the BS is already transmitting to this one

Me with maximum transmission power. For example, traffic in a direct channel is transmitted at a high level for a predetermined time. The MS can send numerous requests to increase power. Alternatively, MS may report too many erasures. Erasure occurs when the number of bits accepted without confidence in their original value exceeds a threshold. Otherwise, the MS transmits a message informing the BS that the set value for its external circuit is high or the current has the maximum permissible level for a long time.

The second type of initiator corresponds to the situation when the expected response is not received from the MS, or an unexpected response is received (8). This situation includes the absence of confirmation from the MS of receiving a message from the BS that requires confirmation. To activate the initiator, this message can be transmitted a predetermined number of times. This number can be constant or change with broadcast messages. In the same way, the BS can accept in the return channel from the MS repeated messages that require confirmation and were received after the transmission of confirmation from the BOS. -

The third type of initiator corresponds to a low quality of the reverse channel, for example, a situation where the frame error rate (FRF) of the reverse channel exceeds the threshold level. Alternatively, the reverse channel may be held high for a predetermined time. Another situation may be Fr

Зз5 High set value for return channel. The BS, which is to be added to the AG, also has initiators and - the restoration of the communication session, which initiate this process. The most important initiator is a message from the CBS about the presence of potential difficulties associated with this MS. In this case, the BS starts searching for signals from this one

MS.

The MS can also use different communication session recovery initiators to enter the communication bean recovery. The first type of initiator corresponds to the situation when the received signals have an abnormally large c number of errors. For example, sweeps in the forward channel in a moving window may exceed a predetermined threshold level. In one embodiment, this threshold is 12 consecutive erased frames. In this ;" in this case, the MS may turn off its transmitter and turn it on again when at least 2 consecutive forward channel frames have no erasures.

The second type of initiator of the communication session recovery for the MS corresponds to the case when the MS receives power control commands from the BS-I instructing to increase the power. The BS may have difficulty receiving reverse channel signals due to significant losses on the way from the MO. o The third type of communication session recovery initiator corresponds to the absence of confirmations from BS on

Go! back channel messages that require confirmation. This is the initiator of retransmission attempts.

Similarly, the initiator can be an improper response or no response from the BS to the MS message. A similar type of initiator corresponds to the reception of repeated direct channel messages that require 4) confirmation, immediately after the actual transmission of this confirmation from the MS.

The fourth type of communication session recovery initiator corresponds to the case when the MS transmits at a high level for a predetermined time. This means that the return channel does not pass to the BS with sufficient energy.

In one embodiment, flexible are used for one or more session recovery initiators

F) rapids. Triggers may be based on multiple transmission attempts in system 10. These attempts are often made at the channel level between the signaling and physical channels. The channel layer is called layer 2 and is discussed below. In the system 10, capable of restoring the communication session MS 38 performs the procedure of restoration because to maintain the communication session when the communication channel, for example, the direct channel, deteriorates. The initiator often initiates session recovery when a parameter or metric crosses a threshold. These thresholds can be dynamic with adaptation to conditions in the system and environment. Thresholds may also be adjusted according to the history or statistics of the system 10.

In one embodiment, the number of retransmissions in the reverse channel or the time between successive erasures, 65 or switching off of the transmitter of the MS 38 may be determined by instructions transmitted from the system infrastructure 10, such as the BSI 32 and/or the CBS 26. In another embodiment, a fixed time is determined for a particular action parameter,

such as the maximum number of retransmissions allowed. The closeness of the current level of transmission from MS 38 to a predetermined maximum can initiate the restoration of the communication session. Other initiators can be the quality of the direct channel, determined by the erasure of transmissions in the current AG, the deficiency of power control in the inner circuit, when the desired VSSH MS 38 is different from that provided by the outer circuit, etc. Other embodiments may use a combination of a specific parameter and MC condition as triggers.

The infrastructure of the system 10 can provide MS 38 with information that can be used to determine the thresholds of the initiators of the restoration of the communication session and to select fixed parameters provided by the MS 38 for use as thresholds. In one embodiment, a typical number of attempts to retry a communication session that is experiencing difficulties or is lost. Other embodiments use direct channel loading to set and correct thresholds. Some embodiments provide for the use of the location of the MS 38 in the system 38, for example, to the sector of a particular cell. Other embodiments consider the day of the week and/or time of day to coordinate with the known traffic pattern of the MS. A combination of any of these mechanisms can be used if necessary.

In the system 10 (Fig. 1, 2), each BS 32, 34, 36 transmits service information to the MS with which it has a connection.

The service information for each BS 32, 34, 36 includes a corresponding list of neighboring BSs, which identifies the corresponding shifts of the PS code of the neighboring BSs.

CBS 26 (Fig. 4) responds to any of the initiators by establishing infrastructure communication with BS1 32 and

BS2 34. According to one of the embodiments, the method 100 of restoring the communication session is initiated as illustrated in Fig.b.

Fig.5 contains a graph of signal quality for an example when there is time to identify MS 38 that has a potential problem.

In one of the embodiments of the method 100 of restoring the communication session (Fig. bA, 68) by operation 102 BS1 32 sends to

MS default channel assignment for a group of neighboring BSs. BSs of this group are suitable for reestablishing a communication session and have the necessary software and/or circuit support for this. These BSs have service areas that overlap the service area. broadcast of the BS sending the neighbor group. Assignment of channels c ov By default, the code indices of these channels used by BSs of the neighbor group, including BS2 code 34, are identified. Each of the BSs of the neighbor group capable of resuming the communication session has an extension code for (8) silence, which will be used for identification of the MS that needs to restore the communication session. In one embodiment, the expanding code is a Walsh code. BS2 34 sends a retransmission attempt initiator to MS 38 (operation 104), which sets the number of retries allowed by this MS to initiate operations c z z Reestablishing a communication session. After that, the BST 32 determines whether the initiator of the restoration of the communication session has taken place (operation 106). If not, it waits for such an initiator to appear. Otherwise, operation -- 108 is performed, by which all BS SG BS1 32 are instructed to transmit in their default channels corresponding to MC 38.

Some of the SG BSs may not establish a communication channel due to the weakness of the forward or reverse channel, however, each SG BS starts transmitting to MS 38. Multiple transmissions provide stronger forward channel signals for MO 38 and a more reliable reverse channel to CBS 26 cha

According to this embodiment, the number of repetitions of the reverse channel message, or the time between successive erasures, is determined by the CBS 26 and sent to the MC 38 via the radio channel by special messages and broadcasts. Another embodiment uses a constant parameter that is different from the other parameters.

One embodiment uses a function of MS conditions, which can be the proximity of the actual transmission level of the MS 38 " to the maximum or the quality of the direct channel, determined by erasures in the current AG. Other conditions in the MS can be determined by the deficit of the internal circuit, i.e. the difference between the desired VSH and the VSH provided by the internal circuit of the KP. Other embodiments combine conditions in the MS with the type of transmission. ;" The allowable number of retries may be adjusted according to the statistics of lost or broken communication sessions. For example, an average number of retries above which most broken communication beans do not recover can be used. Other considerations include direct channel load, location of -I MS 38 and/or time of day or date. In the latter case, the traffic structure of the MS affects the number of MSs that require quick restoration of the communication session. o KBS 26 (Fig.bA) determines the current AG MS (operation 110), after which it initializes the PNP timer (operation 112) and

Go! transmits PNP (operation 114). Here, the system 10 will transfer the communication channels from the default channels. The default channels are available for use by any MS of the system 10 and therefore must be optimized. If the MS - 38 uses this default channel, another BS cannot use this channel BSs in SG 4) are instructed to start transmissions on the default channels.This is the initiation of communication transmission conditions.

If the CBS 26 has received a message from the MS 38, which notifies about the completion of the communication transfer (operation 118), operation 120 is performed, which terminates the communication channels of the MS 38 with members of the SG in the default channels. dv Next, operation 124 is performed. If the communication completion message was not received, the CBS 26 checks whether the PNP timer has expired (operation 122). If so, the corresponding channels are terminated by default

F) transfer to MS 38, by operation 124 the restoration of the communication session is canceled and the use of the default channel and the new channel is stopped (operation 125). Operation 126 restores normal operation.

If the timer has not worked (operation 122), waiting for a message about the completion of the 6o Communication transfer from MS Z8 (operation 118) begins.

Fig. 6B illustrates part of the method 100, where the operation 110 includes the initialization of the timer (operation 130). KBS 26 checks the receipt of PVA from MS 38 (operation 132). If the PVSP was accepted, operation 134 is performed, which includes the neighbors that were included in the PVSP in the AG. Otherwise, it is checked (operation 138) whether the timer (initialized by operation 130) has worked. If yes, the check is performed by operation 144, if not - b5 The check is performed by operation 132. After operation 134, if the reverse channel has been improved (operation 136), the CS determines whether there are neighboring BSs that received the signals of MS 38, but were not included in the PVSP . These neighbors were called listening neighbors (SS) and they are added to the AG by operation 142, after which the procedure returns to operation 112 of Fig.bA.

If the timer has run out and the PVSP was not accepted, the KBS 26 determines (operation 144) the presence of neighboring BSs that have received the signals of the MS 38, i.e. SS. If there is no SS (operation 144), the communication session recovery is stopped (operation 148) and the communication session is interrupted.

Operation 110 checks whether the MC transmitter 38 is turned off. If it is turned off, the CBS instructs

MS 38 turn on the transmitter (operation 110).

Fig. 7 one of the embodiments illustrates the method 200 of restoring the MS communication session. By operation 202, the MS establishes /o communication with BS AG(0). This identifies AG. If the session recovery initiation has occurred (operation 204), operation 208 is performed. The session recovery initiator may be one of those discussed above, or one that meets the need to rescue the MS 38, that is, because the MS 38 may loses the direct channel. If there was no initiation, operation 206 is performed. Operation 208 determines whether the transmitter of MC 38 worked. If so, operation 214 is performed, if not, MC 38 checks the status of the initiator (operation 210). If the initiator state indicates that the MS 38 /5 intends to turn off the transmitter, operation 212 takes appropriate action, followed by operation 214.

If none of the initiators indicates an intention to turn off the transmitter, operation 214 of setting the timer is performed. The wait timer is checked by operation 216 and its countdown is started by operation 218. If the timer has not expired, it is again checked (operation 222) whether the MC 38 has returned to normal mode, after which normal mode continues (operation 206) or a transition back to waiting occurs. working out 2 hours of the waiting timer.

If the transmitter MC 38 is turned off, operation 220 turns the transmitter on. During the U period, the MO 38 transmits a predetermined header that contains transmission information to the MS 38, but not data or symbols.

By operation 228, MC 38 transmits data to the PVSP. If PNP (oper. 228) or confirmation of PVSP was accepted, MS 38 endures delay X, after which it updates AG. If neither PNP nor PVSP was accepted (oper. 230), operation 232 checks that the PVSP was not transmitted more than the permissible number of times. If the PVSP can be transmitted again, ie this maximum has not been reached, operation 228 is performed and the PVSP i) is transmitted again. If this maximum has been reached, operation 236 terminates the communication session recovery.

According to another method of restoring the communication session, the KBS 26 informs all capable neighbors of the BOS 32 about a potential problem. CBS 26 instructs MS 38 to turn on the transmitter and instructs BS SG to receive MS 38. After detecting a signal from MS 38, each BS SG transmits a report. Reports are accepted from the BS subgroup, which includes all BS SG or a part of BS. The CBS 26 informs the MS 38 about the default channels of each BS of this SO subgroup, which use these channels to initiate communication with the MS 38.

According to yet another method, a subgroup of the neighbor group is determined based on the last transmitted o

PVSP But this PVSP can be accepted with errors and then this PVSP is used to detect the fallacy of this subgroup. For example, if the last PVSP identifies BS1 32 and BSZ Zb, but MS 38 after that sent

The PVS, which identifies BSI1 32 and BS2 34 and was not accepted, the restoration of the communication session is interrupted. KBS 26 establishes an infrastructure network with BSZ Z6, and BSZ 36 starts transmissions to MS 38 in the default channel.

But MS 38 believes that in order to restore the communication session, communication with BS2 34 should be established and prepares for reception in another channel by default. Transmissions from the BSZ 36 become redundant and create additional noise in the system 10.

When the resumption of the communication session is initiated by the MC 38, a timer may be used to delay this;" initiation after the activation of the initiator of the recovery of the communication session. The time period for this timer is set by the CBS 26. After the timer expires, the MC 38 transmits a permanent header predetermined by the CBS 26 in the return pilot channel. In another embodiment, the header has a variable length defined by the -AND system operator. After the transfer of the header, the MS 38 sends a message about the changes of the forward channel.

This message can be a PVSP, which is sent several times for reliable reception in BS2 34. o Combinations of the above methods provide a number of advantages. In one of the embodiments, the method of restoring the communication session

Go! based on the environment of radio transmissions from the BS of the cell. When the number of BSs capable of restoring a communication session is small, for example, 2, the KBS 26 instructs all neighboring BSs to transmit in the default channel. AG - is updated and the MS 38 transmitter is turned on immediately. If the number of BSs capable of reestablishing a communication session is 4) greater, the CBS 26 instructs the neighboring BSs to receive signals from the MC 38. After a delay that allows the neighboring BSs to report the possibility of receiving signals from the MC 38, these BSs are instructed to use default channels. If within a predetermined period a PVSP has been received from MS 38, BS, OV specified in the PVSP, are instructed to use the default channels. If the direct canap works properly, i.e. the specified number of consecutive frames are received without errors, the control commands

F) powers sent in the power control subchannel are considered valid. Figure 8 illustrates the architecture of the wireless communication system 10 of Figure 1 in a level structure format. The architecture 700 includes three layers: a signaling layer 702, a channel layer 704, and a physical layer 706. The signaling layer provides upper-layer signaling 708, data service 710, and voice service 712.

Signal layer 702 serves voice and packet data, simple circuit data and simultaneous service of voice and packet data. The protocols and services of this level correspond to the two lower levels. The channel layer is divided into channel access control sub-layer 714 (CAC) and intermediate access control sub-layer 716 (CAC). The application and signaling protocols of layer 712 use the service provided by sublayer 65 of 714 KDC. The channel layer 704 serves as an interface between the upper layer protocols and the application part of the signaling layer 702 and the physical layer 706. The efficiency sub-layer 716 also includes multiplexing and the unit 722 for ensuring the quality of service (Y0). The channel layer 704 connects the signaling layer 702 with the physical layer 706. The physical layer 706 is formed by the physical channel 724 of transmissions.

Fig. 9 contains time diagrams of the operation of the system 10 (see the methods illustrated in Fig. bA, 6B, 7). The horizontal axis corresponds to time, the vertical axis to different transmission channels. BS1 32, which is the source, is shown in the middle, where information is transmitted to MS 38 in the information channel. Two channels are illustrated for MS 38: their transmission channel and the XX reception channel. Two Kx modes are given for the reception channel. and KHo. The BS target is BS2 34. Shown is the default channel and the new channel used to communicate with MS 38 after handover.

The process begins with the MS receiving 38 transmissions from the first AG (AG(0)). MS 38 simultaneously transmits in the 70 information channel to BSI1 32. At that moment, the initiator of the restoration of the communication session reveals itself, and BS1 32 and MS 38 recognize this initiator. The initiator can be a normal event, for example, the continuation of sending power control requests from the MS 38 to increase the transmission power of the direct channel, or individual events. MS 38 and BS1 32 can recognize the initiator not simultaneously. Often the MS 38 can recognize the initiator before the BS1 32.

After identification of the initiator at the moment of its BS1 initiates the transmission from the neighboring BS2 34 in the /5 channel by default. Such initiation can be carried out through the CBS 26. At time 5, BS2 34 starts transmitting in the default channel in parallel with the same transmissions from BS1 32. After detecting the initiator, MC 38 turns off its transmitter for a predetermined waiting period. At the time of departure, this period ends and MS 38 transfers the title during the ХУ period. Simultaneously, AG MS 38 changes from AG(0) to AG(1). BS identified in

AG(1) is all BSs listed in the latest PVSP. In another embodiment, AG(1) can also contain all neighbors of BS1 32.

At moment and, the header ends and MS 38 starts transmitting the current PVSP. In response to the reception of the PVSP at the time i5, BS1 32 and BS2 34 at the moment (5; transmit PNP. The PNP signals at the time (5 change AG to AG(2). At the same time, the next PVSP is transmitted at the moment ii; and PVSP are transmitted periodically for identification signals received in MS 38. p

At its moment, BC2 34 starts transmitting on a new channel for MC 38, which at its moment 5 transmits a PZP, which initiates the completion of transmissions for MC 38 in the default channel. In the case illustrated in Fig. 9, restoration i) of the communication session begins at the moment io and ends at the moment o. Next, BS2 34 becomes the current source for MS 38.

A different procedure is performed for the KxX reception channel. Here AG(0) remains active until the moment and 5, after which MC 38 continues to receive from AG(0) for a predetermined time X, after which it changes AG(0) to

AG(1), which includes only those BSs that can receive signals from MS 38. At the moment of response to PNP "7, AG(1) changes to AG(2). This procedure corresponds to the option when only those neighboring BSs , which are capable of receiving signals from MS 38, are instructed to transmit in the corresponding channels by default.

After the communication session recovery is completed and the communication transfer is completed, the MS 38 must determine the initial me) level of the transmission power. In one embodiment, system 10 (FIG. 1) uses a closed-loop power control loop to correct transmission power levels. In other embodiments, open loop power control is used for this, when this control is carried out through the transmitter (MS or BS) without direct involvement of the receiver. For example, open loop power control of the reverse channel requires the MS to adjust the transmission power in the reverse channel based on the level of signals received from the BS in the forward channel. The closed loop power control extends the open loop by introducing the active participation of the receiver in the /- s power correction process. For example, to control the power of the reverse channel in a closed circuit, the BS compares the power level of signals received from a certain MS with a threshold value, and then, based on this;" comparable, instructs the MS to increase or decrease the transmission power. For its part, the MS monitors the power level of the direct channel signals and sends the direct channel quality indicator back to the BS. Closed circuit

It is used to compensate power fluctuations associated with fading, for example, fading -I Relay, of a given channel.

Directly after the transmission of communication and before establishing control of the power of MC 38. starts transmitting at the initial power level. This level may be the one that occurred before the shutdown

Go! transmitter MC 38. This level can remain unchanged until the closed loop starts to work

Power control. - In another embodiment, the transmission power level is gradually increased at a predetermined rate, starting from that which occurred before the transmitter was turned off, until the power control operation begins.

The growth rate is usually set by BS1 32 and/or BS2 34 and can be constant or variable.

Growth continues until the closed-loop power control function is restored.

In yet another embodiment, session recovery begins with open-loop power control based on the total received energy of the frequency band. This procedure is similar to the access procedure and can be

F) corrected for BS visible from MS. Open-loop monitoring continues until the closed-loop operation begins. Fig. 10 illustrates power corrections according to this embodiment. The horizontal axis shows time, and the vertical axis shows the transmission power level. At the moment y/, the transmission power has the initial value of Viven. After the first time period at time 2, the transmission power is increased by a predetermined incremental value, which may be fixed or variable and increasing or decreasing with time. In one embodiment, this value is adaptive and depends on the conditions in the system 10, increasing or decreasing from time to time. Finally, after a certain period, the transmission power level reaches a maximum and remains at this level until the closed-loop power control operation begins. 65 According to another embodiment, the initial transmission power is based on the quality of the received pilot signal, that is, the pilot Eo/o or the pilot Eo for the BS AG. In the open circuit of power control, the transmission power is determined by the ratio T y-(-КХУ)-К, where К is the cumulative correction constant, ТТ , is the transmission energy of the reverse channel and К, is the received energy of the forward channel. In the closed circuit of power control, the transmission power is determined by the ratio T X-(-K.-Knu(Yu), where y() is an additional variable of cumulative correction.

The member (knu(0). is denoted by V. In another form, the relation Tk -knu(Y.

The V value of previous gears is used to determine the initial power for new gears.

This new power level is calculated by the formula T,(0--КДО-ГО-К(0)), where ТХ(0) is the transmission energy before the communication session is restored, К (0) is the received energy before the communication session is restored yakuza Thus, the transmission power is adjusted according to the previous ratio of the transmission power level to the received 7/0 power level.

Fig. 11 illustrates a wireless device MS 38, for example, a cellular phone or a personal digital assistant (PAA) in the system 10 of Fig. 1. MS 38 has an antenna 300 for reception and transmission, to which an antenna switch is connected, which isolates the receiving channel from the transmitting channel. The antenna switch is connected to the receiving circuit 308, which forms the receiving channel, and to the amplifier 304 and the transmission circuit, which forms the transmission channel. The amplifier 304 is connected to a power correction unit 310 which provides control of the amplifier 304. The amplifier 304 receives signals for transmission from the transmission circuit 306.

The signals received from the antenna 300 are sent to the power control node 314, which implements a closed-loop power control circuit and is connected to the communication bus 318. The bus 318 provides communication between the MC modules 38 and is connected to the memory 322 and the recovery correction node 318. Memory 322 stores computer instructions for various operations and functions of MC 38. Processor 320 performs operations stored in memory 322.

In normal mode, the power control node generates and sends a power control signal to the power correction node 310 through the multiplexer 312. The node 310 also sends a power control signal to the amplifier 304, setting its gain level.

During the restoration of the communication session, the MS 38 may turn off the transmitter. When the transmitter is then turned on, a communication completion signal is sent to the recovery correction node 316, which instructs the node 316 to generate a predetermined power control signal according to any of the schemes discussed above i) setting the initial transmission power of the reverse channel or according to with a different method. The communication completion signal is also sent to control the multiplexer 312. After the communication session is restored, the signal generated by the recovery correction node 316 is sent to the transmission power correction node 310 and at the same time the closed-loop power control begins. After resuming the operation of the closed circuit, the communication completion signal is canceled and the multiplexer 312 selects the power control signal generated by the power control node 314 for the correction node 310. co

The operations of the recovery correction node 316 may be performed by the microprocessor 320 according to program instructions, or these operations may be performed schematically. me)

In one of the embodiments, certain operations of MS 38 or BS1 32 are considered as special events, which are determined by different conditions and procedures that can cause a false appearance of the initiator. In other words, these events can create a situation where an irrelevant trigger is fired. One of these events is the search for the location of the MOS. MS 38 receives instructions to conduct a search for the Global Radio-Determination System (55P) on a different frequency. ZZR gives information about the location of MS 38. Such a search is carried out periodically. "

Of course, MS Z8 a rgiogi has information about the schedule of such searches. In other embodiments, c)c may provide for any number of special events during which initiators should be ignored.

Other events may include MC 38 actions during which the initiator should be ignored. In such cases MS 38;" informs BS1 32 of the original cell about a special event. In one of the embodiments, a special event is a search for a candidate frequency, when the MS 38 is tuned to another frequency to search for neighboring BSs on this frequency. This improves the transition between frequencies, for example, switching from the frequency of the personal communication system (POS) to the cellular -I frequency. In the case of such a special event initiated by the MS 38, the MS 38 instructs the BS1 32 to ignore the initiators

MC 38 for a certain period or until further notice. o According to one of the embodiments, to eliminate false initiators during special events, the original BS1 32

Go! transmits to MS 38 a schedule of searches, which includes at least the start time and duration of the search. MC 38 prohibits initiators from initiating the resumption of a communication session during a special event. - In another embodiment, MS 38 informs BS 1 32 about a special event that is about to occur. In response, MC 1 32 can 4) approve this event, ban it or reschedule it. The MC 38 is hereby instructed to disable the session recovery initiators during the special event.

Therefore, a new and improved method of maintaining communication in the wireless communication system was proposed. dv When the communication channel between the MS and the corresponding BS deteriorates, the MS together with the infrastructure prepares in advance

BS for possible support. The primary BS contacts all possible auxiliary BSs. Capable of recovery

F) of the communication session, the neighboring BS has a default channel adapted for soft transmission of communication with the MS. This ka channel is used only temporarily during the initial phase of communication transmission. Each auxiliary BS is instructed to use the default channel for auxiliary transmissions, which are considered as session recovery operations. The MS enters soft handover communication with the auxiliary BS using the direct channel as the default channel. After that, the auxiliary BS initiates transmissions in another channel. After completing the communication transfer, the auxiliary BS stops transmissions in the default channel to the MO. In one of the embodiments, the original BS provides the MS with a list of neighboring BSs capable of restoring the communication session in an additional message even before difficulties appear in the communication channel. Thus, in situations where the direct channel is lost 65 BEFORE receiving handover information, the MS has enough information to perform handover.

In another embodiment, the adjacent BS2 34 is assigned multiple channels by default. This increases the ability of the system 10 to restore the communication session. Each neighboring BS can then participate in reestablishing a communication session with more than one MS. In this case, before reestablishing the communication session, the original BS1 32 sends to

BS2 34 an identifier corresponding to several channels associated with BS2 34. MS 38 and BS2 34 store a deterministic function, such as a hash function, to map identifiers to a particular channel.

A hash function, in particular, is used in a pseudo-randomized procedure. In addition, the MS 38 is assigned an electronic serial number, which can be stored in the MS 38 or sent at the beginning of the communication session recovery. At the same time, BS1 32 sends the electronic serial number of MS 38 to BS2 34, which simultaneously with MS 38 applies a predetermined function to calculate the appropriate default channel. 70 The hash function allows you to find a keyword in a set of words of a data structure in exactly one attempt. A hash function maps its argument to a result of a predefined type. A hash function is deterministic and changes its state, that is, the output value depends only on the argument, and the same arguments give the same results. The hash function minimizes collisions, i.e. getting the same value from different arguments. The distribution of hash function values is uniform, that is, the probability that the hash function will return 7/5 of a particular value is approximately equal to the probability that the hash function will return any other value. Other embodiments provide for the use of other cryptographic functions to identify multiple channels by default when reestablishing a communication session.

During the restoration of the communication session, the BS does not control the level of the transmission power of the MS. When the MS resumes the transmitter operation, a decision is made to select the transmit power. In one of the embodiments, the initial power level of the header and PVSP transmission is determined in advance, before the start of the communication session recovery.

The initial level may be fixed or dynamically adjusted based on system configuration, environmental conditions, geographic conditions, usage history, or other factors affecting communication.

MS 38 (Fig. 1) determines the level of transmission power of the header and PVSP. Fig. 12 illustrates various procedures for correcting transmission power. In one of the implementations (Fig. 12a), the header and PVSM are sent with a pre-determined interval. The transmission power level is determined by a fixed value P fik, which can be the last transmission power level before the start of the communication session recovery or the difference, increase and) or decrease of the last corrected level of the full transmission power of the MS 38 after the last transmitter shutdown. In another embodiment, the transmission power level is calculated as a function of the previous transmission power level, for example, by adding an incremental value /. In one embodiment, the power level of

Z transmission is constant and its values are sent in advance by the BS to the MS. In another embodiment, this constant level is determined according to MS limitations, such as transmitter limitations. --

At moment / the first header is transmitted, and at moment 2 the PVSP. The title and PVSP are transferred to Ge) the moment of. In a typical embodiment, the header is a return pilot signal that is active during the transmission of the PVSP.

At the moment of departure, the K. interval begins, which ends at the moment of Her m. At the moment of i, the next i is transmitted. with 5 headings. This process continues until the MS 38 receives from the BS1 32 an acknowledgment of receipt of the PVSP. uh-

The confirmation can be a PNP message, or an acknowledgment of the PVSP of level 2. If the MS 38 does not accept the PNP or confirmation within a predetermined time, the MS 38 stops the transmission of the header and the PVSP and cancels the restoration of the communication session.

The transmission power level is again controlled each time the MS 38 determines that the quality of the "forward channel" is sufficient. In one embodiment, the quality criterion is satisfied by two consecutive frames of a direct 8 s channel received without errors. According to one embodiment, as soon as the quality of the forward channel becomes sufficient for and sufficient for transmission and control of the power of the reverse channel is restored, the MC 38 resumes the transmission of "" normal traffic and the subscriber equipment continues to transmit PVSP with an interval of k/( but without a header.

The channel's ability to satisfy the transmission quality criterion is usually determined by the system configuration and parameters, and several criteria can be used. In addition, the criteria can be dynamically adjusted according to the operation of the system.

Fig. 1288 illustrates another embodiment in which the transmission power level is incrementally adjusted during transmitter re-initialization. The first header and PVSP are transmitted at the first P1 power level. The ratio of the total transmission power of the header and PVSP to the transmission power of the header and, therefore, the pilot channel,

Maintained at a predetermined level in (dB). The header and PVSP are repeated with an interval of ki, as in the embodiment of Fig. 12a, however, the full transmission power is increased in successive steps. The increase size can be incremental with a predetermined step and defined for the system. In another version, the increment for

MS is determined in BS. In other embodiments, the time intervals can be variable, and the times of transmission of the header and

PES may also change over time. The transmission power level increases to the maximum value R umakh | remains at this level for subsequent transmissions. In one embodiment, the level of P is determined in the BS1 32 and transmitted to the MS 38. Other embodiments may use a fixed value of P". After receiving the PNP or iF) confirmation of the PVSP level 2, the MS resumes normal transmissions and receives control of the power of the reverse co-channel from the BS In another embodiment, transmission of the header and PVSP continues until PNP or Layer 2 PVSP acknowledgment is received, and reverse channel power control is resumed by the BS when the forward channel reception quality reaches the desired level.

Fig. 13 illustrates a method 400 of re-initializing the transmitter in the MS during the restoration of the communication session according to one of the embodiments. By operation 402, the transmission power Ru of the header and PVSP is determined as a function of the last level P tor of the transmission power of the MS before the start of the communication session recovery. In one of the embodiments, P thx is set equal to P tuhsrr. kCorrected according to the full power Rghoid- received in the MS before 65 Reestablishment of the communication session and the full power P dhmegmu received after the start of the restoration of the communication session, according to the equation in Fig. 13B (operation 402). The initialized transmitter transmit power is the last transmitted power, corrected for the difference, increase or decrease of the full power received by the MC 38 since the transmitter was last turned off. The header and PVSP are transmitted with this power level. Other embodiments provide a predetermined value for the initial transmission power level. The MS is waiting for confirmation from the BS about the successful reception of the PVSP. In this embodiment, the MS verifies the receipt of the PNP or (in other embodiments) the receipt of the Level 2 PVSP confirmation (operation 404). Another embodiment involves checking the reception of the PNP or confirming the level 2 PVSP. The MS transmits the header and the PVSP at K/ intervals. In the intervals between transmissions, the MS continues to check the receipt of PNP. After receiving the PNP in the interval K 4, the MS returns to normal traffic processing (operation 406) and control of the power of the return channel 7/0 continues with instructions from the BS. If the PNP was not accepted in the K 4 interval, the MS prepares to transmit the next header to the PVSP. The MS compares the current Ru transmission power with the maximum Rudakh level (operation 408). In one embodiment, a reception quality check is performed after operation 406. In one example, reception of two consecutive frames without errors is checked. If such two frames were not received, operation 408 is performed, otherwise the header and PVSP are transmitted with a controlled power level of /5 and the transition to operation 416 occurs.

Although the MS operation 404 verifies the arrival of the PNP or other confirmation of the PVSP, control of the power of the reverse channel is restored after receiving two consecutive error-free frames. The result of such an approach is the exit from the process of increasing the transmission power for the header and PVSP. As long as P is Ruah, processing continues to operation 412 of raising P tu. This increase is done in fixed or variable 2o increments. Other embodiments provide for the transmission of multiple frames at each transmit power level prior to each boost. In operation 414, the MS transmits the header and PVSP with the adjusted power level, after which operation 416 is performed to determine whether the time period for reinitializing the transmitter has expired. If P tu is at least Rudau, transfer operation 410 is performed with power P Rudau. If the time period has not expired (operation 404), there is a transition back to operation 404, and if it has expired, the MS terminates the restoration of the communication session by operation 418.

In one of the embodiments, in order to avoid unnecessary initiations of reestablishing the communication session in the BS, the MS notifies about i) a time break to search for a candidate frequency for hard transmission of communication. During this search, the MS may leave the current frequency for some time to initiate the resumption of the communication session. The restoration of the communication session is prohibited in order to notify the BS that in fact there are no conditions for restoration. с зо Parallel to the reinitialization of the transmitter, the MS waits for the restoration of the direct channel, which is usually determined by two consecutive error-free frames received by the MS. After this recovery, the return channel power control is turned on. co

Thus, a new and improved method and device for adjusting the power level in a wireless communication system has been described. Examples, embodiments, aspects and drawings are provided for illustration only and are not

35 Exclude other embodiments that correspond to the concepts and scope of the invention. The data, instructions, commands, information, signals, bits, symbols and code elements mentioned in the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or combinations thereof. Although embodiments have been described for circuits of certain polarity, assertion and denial are relative terms and are not limited to low and high logic levels. "

It is clear to a person skilled in the art that the illustrative logic blocks, modules, schemes and operations of the algorithms mentioned in the description of the embodiments can be implemented schematically, programmatically or in combination. The method of implementation of these functions (schematically or programmatically) depends on the specific application and system design limitations. It is clear that schematic and ;" software solutions are interchangeable and their choice depends on the specific applications of their functions. The scope of the invention also includes schemes of algorithms in which the order of execution of the described operations is different.

Logical blocks, modules and operations of algorithms, which relate to the embodiments of the invention presented here, can be implemented through the use of a general-purpose processor, a digital signal processor (DSP), a specialized integrated circuit (ASIC), a specialized set of programmable field logic elements o (ERSA) or other programmable logic devices, discrete key or transistor logic, discrete

Go! circuit components, for example, registers, a processor with PZP, any conventional programmable module and a 5p processor or any combination thereof capable of performing the described functions. - The given description of preferred embodiments enables a specialist to apply the invention. Various modifications of these embodiments and these principles of the invention will allow to build other embodiments without additional invention. The invention is not limited to these embodiments and its scope is determined by its principles and new features.

Claims (7)

The formula of the invention F) GI 1. A method of restoring a communication session in a wireless communication system, which includes: - transmission of a message about the measurement of the pilot signal strength at the first level of transmission power, v - waiting for a predetermined period of time, and - transmission reporting pilot signal strength measurements at the second transmission power level higher than the first transmission power level. 2. The method according to claim 1, which is characterized by the fact that the second transmission power level is the maximum level. 3. The method of restoring a communication session in a wireless communication system, which includes: 65 - initialization of the restoration of a communication session and Y - incrementing the transmission power level before receiving a message about the direction of automatic switching of the mobile station. 4. The method according to item C, which is characterized by the fact that it additionally includes the transmission of a message about the measurement of the pilot signal strength with each transmission power level. 5. The method according to claim 3, which is characterized by the fact that the transmission of pilot signal strength measurement messages is carried out at predetermined time intervals. 6. The method according to claim 3, which is characterized by the fact that the transmission of the pilot signal strength measurement message includes a header message. 7. A power level correction device in a wireless communication system, which includes: 70 - an antenna, Y - a processor connected to the antenna, - a transmission circuit connected to the antenna and the processor, and - a processor having a first circuit for incrementing the transmission power of the message about the measurement of the pilot signal strength during the restoration of the communication session and the second scheme for maintaining the transmission power below /5 of the maximum level. 6) (ze) «- (ee) (ze) and - - and? -i (95) (ee) - 70 syu» ime) 60 b5