MXPA01004734A - Wireless communications methods and apparatus employing paging attribute descriptors - Google Patents

Abstract

A paging attribute descriptor (PAD) indicates the content of a page message is transmitted in a first time slot and/or a succeeding second time slot of a physical channel, and the page message is transmitted in the second time slot. The second slot may be, for example, a Digital Control Channel (DCCH) slot mapped on a physical channel (DTCH) of an IS-136 system. The transmitted PAD is recovered at wireless station, which then determines whether to recover the page message based on the recovered PAD, e.g., if the PAD indicates that the page message is an empty page message, a page message addresed to another wireless station or a page message that includes control information that has changed. For example, in an IS-136 compliant system, the PAD may be transmitted in the coded superframe phase (CSFP) field of a Paging Channel (PCH) message transmitted in a Digital Control Channel (DCCH) slot, or in reserved bits of a slot preceding a PCH message.

Description

METHODS AND APPARATUS OF WIRELESS COMMUNICATIONS THAT USE DESCRIPTORS OF PAGING ATTRIBUTE BACKGROUND OF THE INVENTION The present invention relates to wireless communication systems and more particularly to methods and apparatus for control communication in wireless communication systems. Cellular radio systems have been in operation in the United States since the early 1980s. In a typical cellular radio system as shown in Figure 1, a geographic area (eg, a metropolitan area) is divided into several smaller contiguous radio coverage areas ( called "cells") such as cells C 1 -C 10. Cells C 1 -C 10 are served by a corresponding group of fixed radio stations (called "base stations") B1 -B10, each of which operates on a subset of the radio frequency (RF) channels assigned to the system. RF channels assigned to any given cell can be reassigned to a distant cell according to a frequency reuse pattern as is well known in the art. Mobile phone users (mobile station subscribers) in C 1 -C 10 cells are provided with portable (hand-held), transportable (hand-carried) or mobile (car-mounted) wireless stations such as the M 1 -M9 stations , each of which communicates with a nearby base station. The . base stations B1 -B10 are connected to and controlled by the mobile station services switching center (MSC) 20. The MSC 20, in turn, is connected to a central office (not shown in the figural) in the telephone network public landline switch (cabling) (PSTN) or a similar facility such as an integrated system digital network (ISDN). The MSC 20 switches the calls between the line subscribers and the mobile station, controls the signals to the mobile stations, compiles the billing statistics and provides the operation, maintenance and testing of the system. In each cell, at least one RF channel (called "control" or "paging / access" channel) is used to carry the control or monitoring messages, and the other RF channels (for example, "voice" or "voice" channels). "dialogues") are used to transport voice conversations. When activated (lit), each of the mobile stations M 1 -M9 enters the idle state (standby mode) and continuously selects and monitors the strongest control channel (generally, the control channel of the cell of the that the mobile station is located at that moment). To detect incoming calls, the mobile station continuously monitors the control channel to determine if a page message directed to it (ie, containing its MI N) has been received. A page message will be sent to the mobile station, for example, when an ordinary subscriber (landline) calls the subscriber of the mobile station. The call is directed from the PSTN to the MSC 20 where the dialed number is analyzed. If the dialed number is validated, the MSC 20 requests some or all of the base stations B 1 -B10 that do the paging of the mobile station that is called through its corresponding cells C1-C10. Each of the base stations B1 -B10 receiving the request from the MSC 20 will then transmit on the control channel of the corresponding cell a page message containing the MI N of the called mobile station. Each of the unoccupied mobile stations M 1 -M 9 which is present in that cell will compare the MI N in the page message received on the control channel with the M I N stored in the mobile station. The mobile station with the coupling MIN will automatically transmit a page response on the control channel to the base station which transfers the page response to the MSC 20. Upon receiving the page response, the MSC 20 selects a channel of voice available in the cell from which the page response was received (MSC 20 maintains an idle channel ready for this purpose) and requests the base station in that cell that orders the mobile station through the control channel that select the selected voice channel. A connection is established once the mobile station has selected the selected voice channel.

Figure 3 shows an illustrative DCCH superstructure including at least three logical channels, i.e., a transmission control channel (BCCH), a paging channel (PCH), and an access response channel (ARCH). The BCC H, which in this example is assigned with 6 DCCH segments, carries supplementary messages. The PCH, which is assigned with a DCCH segment, transports page messages. The ARCH, which is also assigned with a DCCH segment, carries the messages of voice channel assignment or dialogue. The illustrative superstructure of Figure 3 may contain other logical channels, including the paging channels (if more than one PCH is defined, different groups of mobile stations may be assigned to different PCHs). A mobile station operating on the DCCH of Figure 3 needs only to be "aware" (monitoring) during certain time segments (for example, the BCCH and the assigned PCH) in each superstructure and can enter "inactive mode" in all other times. While it is in idle mode, the mobile station shuts down most internal circuits and saves battery power. In addition, by configuring the BCCH as taught in U.S. Patent No. 5,404, 355 to Raith, the mobile station can read (ie decode) the supplementary messages when they lock onto the DCC (e.g. , in the ignition) and later only when the information has changed, resulting in additional battery energy savings while allowing a quick selection of the cell. Typically only a fraction of the page messages • received on the PCH will be directed to the mobile station, such as most messages that would be empty messages ("fill" messages that do not contain pages) or pages for other mobile stations. PC H will usually operate substantially below the capacity limit in order to avoid blocking excessive traffic (and therefore, the delay in the provision of pages towards mobile stations). If blocking problems develop (for example, due to unanticipated demand) in any cell, the operator may assign additional control channels in that cell or use other capacity improvement techniques such as cell division. Therefore, in general, a managed PCH suitably will typically operate at a level well below maximum capacity, even during business hours. Consequently, more frequently, the PCH transports • empty messages. In addition, since a mobile station usually receives no more than a few calls a day, most page messages that are not empty sent to the PCH will be for other mobile stations. To maximize the efficiency of the idle mode, the mobile station must be able to detect whether the received page messages are relevant messages (for example, page messages). directed to this particular mobile station) or irrelevant messages (e.g., empty page messages or page messages directed to other mobile stations) as early as possible in the reception processing (e.g., after demodulation but before decoding) to avoid as many stages of signal processing as possible. Once a relevant page is detected, the mobile station can immediately return to idle mode. To appreciate the possible energy savings from a timely detection of the irrelevant pages, consider a typical PCH in which the page message is sent once every second. This means that there are (60 * 60 * 24 =) 86,400 page messages sent to the mobile station each day. And if for example, the PCH transports non-empty page messages only 10% of the time, the mobile station can avoid processing 90% of the page messages if it can detect the empty pages. further, if only a few of the non-empty page messages are directed to this mobile station, the processing of almost all page messages transmitted on the PCH can be prevented if it can also be detected that the other non-empty page messages are directed to other stations mobile Therefore, the mobile station can effectively be in the idle mode during the PCH reception. The aforementioned U.S. Patent 5,404,355 discloses a technique for grouping information elements and providing an indicator if the mobile station should read the associated information elements. This technique is used in current IS-136 to inform mobile stations of new or changed supplementary information. In the PCH channel, the change signals are provided to indicate to the mobile station that it reads the supplementary information and the end user transmission messages respectively. During the transmission channel (BCCH), the exchange signals are provided to indicate changes, amendments or deletions of the sub-partition of the BCCH channel. Similarly, TIA contribution TR45.5.3.1 / 98.07.14.13 describes a new composite channel (F-QPCH) which indicates whether the mobile station should read its allocated inactive segment in which there may be pages or supplementary information . Each of the mobile stations is assigned with a particular F-QPCH based on its identity. Only a few new mobile stations (designed with the knowledge of the F-QPCH channel) can have a benefit of energy savings. In addition, with the interest of backup compatibility, the F-QPCH channel may have to be introduced into a different control channel after the control channel serves the previous mobile stations. The patent of the United States of America No. ,930,706 for Raith discloses a technique that can save mobile station battery power while being on standby in a control channel. The mobile station re-encodes the format (bit pattern) of an empty page and compares it with the page messages received before channel decoding. Since there is too much redundancy on an empty page, the comparison of the stored vector and the received vector can be achieved safely using only a small fraction of the transmitted data. If the mobile station determines that the received data 5 is an empty page, the mobile station stops further processing. In a refined operation mode, the mobile station re-encodes its paging number (the data used to compact the mobile station for example I MSI / MI N / TMSI) and compares the input data with the pre-stored data. For example, in FIG. 10, the GSM system that interleaves the paging channel over four non-consecutive time segments, the mobile station will be able most often to make a determination as to whether or not to examine the contents in the paging channel afterwards. that you have received only one of the four time segments.

In TIA / EIA IS-95, the paging segment is rather long (80 ms) and the use of this technique would allow the mobile station to turn off, when the page is not present, in a much shorter time. In contrast to the proposal in TR45.5.3.1 / 98.07.14.13 this technique can be applied to any wireless system and does not require new protocols in the control channel. In addition, previous and new mobile stations for a given system do not need to be segregated to different control channels. However, due to the multiple possible types of mobile station identity and PC H messages that may contain pages The multiple implementation of this method must be simulated in an off-line computer so that the mobile station does not make erroneous decisions.

BRIEF DESCRIPTION OF THE INVENTION According to the embodiments of the present invention a paging attribute descriptor (PAD) indicates the content of a page message is transmitted in a first time segment and / or a second successive time segment of a physical channel, and the Page message is transmitted in the second time segment. The second segment can be, for example, a segment of digital control channel (DCCH) mapped on a physical channel (DTC H) of an IS-136 system. The transmitted PAD is retrieved at the wireless station, which then determines whether recovers or not the page message based on the recovered PAD, for example, if the PAD indicates that the page message is an empty page message, a page message addressed to another wireless station or a page message including training control that has changed. For example, in a system compatible with IS-136, the PAD may be transmitted in the coded superstructure phase (CSFP) field of a paging channel message (PCH) transmitted on a digital control channel (DCCH) segment. or in reserved bits of a segment preceding a PCH message. The present invention arises from the realization that energy savings in addition to those provided by conventional idle mode operations and other conventional energy saving techniques can be achieved by using a paging attribute descriptor (PAD) that can be read. quickly and used to determine if page messages are completely processed or not. The PAD may be incorporated within the existing control structures so that major modifications of the wireless communications protocols are not required, and so that existing features, such as the existing page message control signals, may be Still supported further, the PAD feature can be implemented so that the new generation of wireless stations (eg cell phones) can enjoy the advantages and use the PAD feature while the compatibility with the previous terminal designs is maintained. In the embodiments described herein, this can be accomplished by mapping a PAD channel over the existing fields in the paging channel (PCH) messages and / or the digital channel control messages (DCCH) and by structuring the PAD to support page message control signals and modified link quality monitoring techniques. According to one embodiment of the present invention, in a wireless communication system that is operative to communicate on a physical channel defined as a series of repetition time segments, a paging attribute descriptor (PAD) is transmitted in minus a first time segment of the physical channel and a second time segment of the physical channel that follows the first time segment, the PAD indicating the content of a page message. The page message is transmitted in the second time segment. The PAD in a wireless station, which determines whether or not the page message is retrieved based on the recovered PAD. Preferably, the wireless station retrieves the page message if the retrieved PAD meets a predetermined criterion and refrains from retrieving the page message if the retrieved PAD does not meet the predetermined criteria. In one embodiment of the present invention as a signal including the PAD is transmitted in a time segment assigned to a paging channel. The signal is received at the wireless station and demodulated to a sufficient degree to recover the PAD. The wireless station proceeds to additional demodulation of the received signal if the recovered PAD meets a predetermined criterion. In another embodiment, a signal burst representing the page message and the PAD is transmitted on a digital control channel (DCCH) time slot assigned to a paging channel (PCH). The signal burst is received at the wireless station and processed to recover the PAD. The signal burst may represent a physical layer message that includes a coded superstructure phase (CSFP) field that includes the PAD.

In another embodiment, a similar technique is used to transmit a PAD in a packet data control channel (PCCH) time slot assigned to a paging channel (PCH), more particularly, in a packet type field. coded data structure (C DFT). In still another embodiment of the present invention, a first signal burst representing the PAD is transmitted in a time segment preceding a time segment DCCH assigned to a paging channel (PCH). A second signal burst representing the page message is transmitted in the DCCH time slot assigned to the PCH. The second signal burst can be processed sufficiently in the wireless station to retrieve the synchronization information, which is then used to process the first signal burst to recover the PAD. The wireless station can then determine whether or not the second signal burst is further processed to recover the page message based on the recovered PAD, according to another aspect of the present invention, a transmitted PAD includes one of a plurality of group values, a respective one of the group values associated with a respective group of wireless stations. This group value can be retrieved at a receiving wireless station, which retrieves the page message if the recovered group value is associated with a group of wireless stations of which the wireless station is a member.

In another embodiment of the present invention, a transmitted PAD includes a signal indication status of the control information included in a page message. This signal can be retrieved at the wireless station, which determines whether or not the associated page message is retrieved based on the recovered signal. according to another aspect of the present invention, a decision that whether or not a page message is retrieved at the wireless station based on the recovered PAD, is diverted towards one of the recovery of the page message or the resignation of • recovery of the page message. For example, the wireless station may divert the decision of whether or not to retrieve a page message based on a recovered PAD associated with the page message beyond message retrieval from page that the abstention of the page message retrieval, since a page message is lost that is really intended to be for the wireless station that may have a consequence • more important negatives than the unnecessary reading of a page. The deviation can be based, for example, on channel quality. In still another embodiment of the present invention, a wireless station may operate in a first and second mode in which it processes the PADs deferentially. The wireless station can retrieve a page message transmitted on the wireless station if the PAD meets a predetermined criterion and the wireless station is in the first mode. However, if the wireless station is in the second mode, it can retrieve the transmitted page message regardless of the recovered PAD. According to another aspect of the present invention, a wireless station includes a receiver that retrieves a transmitted page attribute descriptor (PAD) from at least one of a first time segment of a physical channel defined as a series of repetition time segments and a second time segment of the physical channel that happens to the first time segment, the PAD that indicates the content of a page message transmitted in the second time segment and that determines whether the message is retrieved or not of page based on the recovered PAD. The recipient may be able to retrieve the page message if the retrieved PAD meets a predetermined criterion and to refrain from retrieving the page message if the retrieved PAD does not meet the predetermined criteria. According to yet another aspect of the present invention, a wireless communication system includes a base station that transmits a paging attribute descriptor (PAD) in at least one of a first time segment of a physical channel comprising a series of repetition time slots and a second segment and time of the physical channel that happens to the first time segment, the PAD that indicates the content of a page message and that transmits the page message in the second time segment. The PAD may be transmitted, for example, in a CSFP field of a PCH page message transmitted in a DCCH segment and / or in a segment that precedes this DCCH segment.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 illustrates a conventional cellular radio system. Figure 2 illustrates a physical channel structure for a time division multiple access (TDMA) wireless communications system. Figure 3 illustrates an illustrative superstructure frame for a digital control channel (DCCH) defined on the RF TDM channel shown in Figure 2. Figure 4 is a block diagram illustrating a mobile station that can be used in accordance with embodiments of the present invention. Figure 5 illustrates an IS-54B compatible segment format for time division multiple access (TDMA) transmissions from the mobile station of Figure 4. Figure 6 is a block diagram illustrating a base station that it can be used according to the embodiments of the present invention. Figure 7 illustrates a segment format compatible with IS-54B for TDM transmissions of the base station of Figure 6.

Figure 8 illustrates a format for a layer 2 structure (L2) that can be used to transmit a page message in accordance with conventional communication standards.

Figure 9 illustrates an ascending segment format for a DCCH that is compatible with the IS-136 standard. Figure 10 illustrates a downlink segment format for a DCCH that is compatible with the IS-136 standard. Figure 11A illustrates a superstructure frame defined on a DCCH compatible with the IS-136 standard. Figure 11B illustrates a hyperstructure framework defined on a DCCH compatible with the IS-136 standard. Figure 11C illustrates the synchronization for the paging structure classes defined for a DCCH compatible with the IS-136 standard. Figure 11A illustrates a superstructure frame defined on a DCCH compatible with the IS-136 standard. Figure 11A illustrates a superstructure frame defined on a DCCH compatible with the IS-136 standard. Figure 12 illustrates the operations for mapping layer 3 messages (L3) into TDM / TDMA segments according to the IS-136 standard. Figure 13 illustrates a format for an L2 structure that can be used to transmit an empty page message according to the IS-36 standard.

Figure 14 il uses a format for an L2 structure that can be used to transmit a non-empty page message according to the IS-136 standard. Figure 15 illustrates a message header for use in structures L2 as illustrated in Figures 13-14. Figure 16 illustrates a data control channel segment format in downlink packet (PCCH) according to the IS-136 standard. Figures 17-24 are illustrations of flow chart of operations to provide an attribute descriptor channel of • page (PAD) according to the embodiments of the present invention.

DETAILED DESCRIPTION 15 The present invention will now be described more fully with reference to the accompanying drawings, in which • which preferred embodiments of the invention are shown. However, this invention can be presented in many forms different and should not be considered as limited to the modalities set forth herein; instead, these embodiments are provided so that this description will be complete and will completely transfer the scope of the invention to those skilled in the art. In the drawings, similar reference numbers are refer to similar elements.

The following description is written in terms of a cellular telephone radio system, although it will be understood that the present invention is not limited to that environment. Likewise, the following description is written in the context of time-division multiple access (TDMA) cellular communication systems, although it will be understood by those skilled in the art that the present invention is applicable to systems that they use other access techniques, for example, in code division multiple access (CDMA) systems such as those that adhere to the IS-95 standard.

One modality and the other In a conventional cellular radio system as shown in Figure 1, a geographic area (eg, a metropolitan area) is divided into several smaller contiguous radio coverage areas (called "cells"), such as the cells C 1 -C 10. Cells C 1 -C 10 are served by a corresponding group of fixed radio stations (called "base stations") B 1 -B10, each of which operates on a subset of radio channels frequency (RF) assigned to the system. The RF annals assigned to any given cell can be reassigned to a distant cell according to a frequency reuse pattern as is well known in the art. In each cell, at least one RF channel (called the "control" or "paging / access" channel) is used to carry the control or monitoring messages, and the other RF channels (called the "voice" channels). "dialogue") are used to carry the • voice conversations. Cell phone users (mobile subscribers) in cells C1-C10 are provided with portable (manual), transportable (hand-carried) or mobile (car-mounted) telephone units, telephone units (wireless terminals) such as the M1-M9 wireless terminals , each of which communicates with 10 a nearby base station. The base stations B1-B10 are connected to and controlled by the mobile services switching center (MSC) 20. EJ MSC 20 in turn is connected to a central office (not shown in figure 1), in the network public switched telephone line of Jínea terrestre. { wired) (PSTN) or a similar installation such as an integrated system digital network (ISDN). The MSC 20 switches the calls between the wiring and the mobile desks, controls the signaling to the terminals ^ cordless, compiles billing statistics and provides the operation, maintenance and testing of the system. 20 When activated (lit), each of the M1-M9 wireless terminals enters the idle state (standby mode) and continuously selects and monitors the strongest control channel (usually, the cell control channel). in which the wireless terminal is located at that time).

To detect incoming calls, the wireless terminal continuously monitors the control channel to determine whether or not a page message has been received addressed to it (ie, • that contains your MI N). A page message will be sent to the wireless terminal, for example, when an ordinary subscriber (landline) calls the mobile subscriber. The call is directed from the PSTN to the MSC 20 where the dialed number is analyzed. If the number marked in validated, the MSC 20 asks some or all of the base stations B1 -B10 to do the paging of the wireless terminal that is called through • its corresponding cells C1-C10. Each of the base stations B1 -B10 receiving the request from the MSC 20 will transmit on the control channel of the corresponding cell a page message containing the M I N of the called wireless terminal. Each one of the inactive wireless terminals M 1 -M9 which is present in that cell compares the M I N in the page message received on the control channel with the M I N stored in the • wireless terminal. The wireless terminal called with the coupling M I N will automatically transmit a page response x on the control channel to the base station which is then transferred to the page response to the MSC 20. Upon receiving the page response, the MSC 20 selects an available voice channel in the cell from which it is received. received the page response (the MSC 20 maintains an unoccupied channel list for this purpose), and request the base station in that cell to order the wireless terminal through the control channel that selects the selected voice channel. A complete connection is established through the wireless terminal that has selected the • selected voice channel. Figure 3 shows an illustrative QCCH superstructure including at least 3 logical channels, i.e., a transmission control channel (BCC H), a paging channel (PCH), and an access response channel (ARCH) . The BCCH, which in this example is assigned with 6 segments DCCH, carries the messages supplementary The PCH, which is assigned with a DCCH segment, carries the page messages. The ARCH, which is also assigned with a DCCH segment, carries the voice channel assignment or dialogue messages. The illustrative superstructure of Figure 3 may contain other logical channels, including additional paging channels (if more than one PCH was defined, different groups of wireless terminals may be assigned to different PCHs). A wireless terminal that operates on the • DCCH of Figure 3 needs only to be "conscious" (monitoring) during certain time segments (for example, the BCCH and its assigned PCH) in each superstructure and can register the "inactive mode" at all other times. While in idle mode, the wireless terminal can turn off most internal circuits and can save battery power. In addition, when configuring the BCCH as taught in the patent of the States U.S. Nos. 5,404, 355 to Raith, the description of which is hereby incorporated by reference in its entirety, the wireless terminal can read (ie decode) the supplementary messages when the DCCH is latched (e.g. on power up) and later only when the information has changed, thus allowing for additional battery energy savings while allowing for quick cell selection. Referring now to Figure 4, there is shown a block diagram to an illustrative wireless terminal 400 that includes components that can be used in accordance with the present invention. In Figure 4, certain components that are relevant for communications over digital channels are shown, although it will be appreciated that other digital or analog components may be used in addition to or in place of some of those components. The illustrative wireless terminal 400 of Figure 4 can transmit and receive the voice and control data. The transmission circuit is generally illustrated in the upper half of FIG. 4 while the reception circuit is generally illustrated in the lower part of FIG. 4. In the wireless terminal 400 of FIG. 4, the user's voice is detected as an analog voice signal by a microphone 100 and then passed through one or more speech processing steps (not shown in Figure 4) before being provided as an input to a voice coder 101. The pre-encoding speech processing steps may include audio level adjustment, band-pass filtering, and digital analog conversion (for example, the 13-bit PCM format to an 8-bit and legal format) followed by the additional high-pass filtering. The speech encoder 101 uses a compression algorithm (e.g., ACELP or VSELP) to compress the speech signal into a stream of lower speed data bits (e.g. from 64 kbps to 8 kbps). The output of the speech encoder 101 is fed to a channel encoder 104 which applies one or more protection and / or error correction techniques to the data stream. For example, channel encoder 104 may use a half-speed convolutional code to protect the most vulnerable bits of the voice coder's data stream. The channel encoder 104 may also use a cyclic redundancy check (CRC) on some of the most significant perceptual bits of the speech encoder structure. Referring again to Figure 4, the control data is generated to the wireless terminal 400 in a fast associated control channel generator (FACCH) 102 and a slow associated control channel generator (SACCH) 103, and the error encoded in the channel encoders 105 and 106 respectively. FACCH messages are transmitted in a mute and burst mode so a burst of voice data is silenced and replaced with a high-speed FACCH burst. In contrast, the SACCH messages are transmitted continuously at a lower speed along with each burst of voice data. In the illustrative embodiment shown in FIG. 4, the SACCH messages are fed to a burst interlayer 22 1 10 distributing the SACCH data over 22 time segments before transmission. With continued reference to FIG. 4, the encoded speech bits from the channel encoder 104 and the FACCH messages from the channel encoder 105 are provided to respective inputs of a time division multiplexer 107 that formats the voice data or the data. FACCH messages in the transmission time segments. The output of the multiplexer 107 is fed to a burst interleaver-2 108 which interleaves the coded voice or FACCH data over two time segments (e.g., segments 1 and 4 in FIG. 2) to decrease the deleterious effects of the Rayleith fading. and thus provide additional protection against channel errors, in addition to that provided by the error coding. This means that each voice time segment contains data from two consecutive voice coder structures or similarly, that each FACCH message is distributed over two time segments. The burst interleaver-2 output 108 is provided as an input to a module-2 adder 109 where the data is encrypted on a bit-by-bit basis by the addition of logical modulo-2 with a pseudo-random key stream provided by an encryption unit 1 15. The inputs to the encryption unit 1 15 can include the value of a structure counter 1 14 that is incremented once every 20 ms (eg, once each TDM structure for a channel of total speed), and a secret key 1 16 that is unique to the wireless terminal. The structure counter 14 is used to update the encryption code (pseudo-random key stream) once every 20 ms (ie, once for each TDM structure). The encryption code is generated using an encryption algorithm that manipulates the bits of the secret key 1 16. (It will be noted that although the encryption technique described above was initially proposed for IS-136, IS-136 currently implements an encryption scheme However, as will be appreciated, the present invention is applicable to systems using the current IS-136 encryption scheme, as well as to systems using other encryption schemes). The data encrypted from the module-2 add-on 109 and the SACCH data interleaved from the burst interleaver-22 1 10 are provided as inputs to a burst generator 1 1 1 which is also provided with a synchronization word (sync) and a digital verification code (DVCC) from a synchronization word generator / DVCC 1 12. The burst generator 1 11 formats the bursts of data each including a synchronization word, DVCC, SACCH data, and data from voice or FACCH as shown in figure 5 (fields G and R are for protection time and rise time respectively). The synchronization word is used for timing segment identification and synchronization, and equalizer training at the remote receiver (ie, base station). The DVCC is used to distinguish the current traffic channels from the traffic co-channels and ensures that the appropriate RF channel is decoded by the receiver. The DVCC can be encoded by mistake with, for example, a Hamming code. As will be seen later, the DVCC and the synchronization word are also included in each of the bursts transmitted from the base station to the wireless terminal. With additional reference to figure 4, each of the message bursts from the burst general 1 1 1 is transmitted in one of the three time segments (corresponding to respective physical channels) of the TDMS (total speed) structure shown in Figure 2 and described above . The burst generator 1 1 1 is connected to an equalizer 1 13 which provides the necessary timing to synchronize the transmission of one time segment with the transmission of the other two time segments. Equalizer 1 13 detects the timing signals sent from the base station (master) to the wireless terminal (slave) and synchronizes the burst generator 1 1 1 accordingly. The equalizer 1 13 can also be used to check the values of the synchronization word and the DVCC received from the base station. The burst generator 1 1 1 and the equalizer 1 13 are connected to the structure counter 1 14 for timing purposes. The message bursts produced by the burst generator 1 1 1 are provided as input to an RF modulator 1 17 which is used to modulate a carrier frequency in accordance with a modulation technique known as quadrature phase shift modulation, coding. differential, displaced p / 4 (p / 4 DQPSK). The use of this technique implies that the information is transmitted by the wireless terminal that is differentially coded so that the 2-bit symbols are transmitted as four possible changes in phase (± p / 4 and ± 3p / 4) in time of the absolute phases. To minimize errors caused by noise in the selected RF channel, Gray encoding can be used to map phase changes adjacent to symbols that differ by only one bit (since the most likely errors result in the receiver selecting a adjacent phase, such errors will be limited to single-bit errors). The carrier frequency for the selected RF channel is supplied to the RF modulator 117 by a transmission frequency synthesizer 118. The burst modulated carrier signal output of the RF modulator 117 is amplified by a power amplifier 119 and then transmitted to the RF station 117. base through an antenna 120. The reception in the wireless terminal 400 can be visualized as the inverse of the transmission. The wireless terminal 400 receives the burst modulated signals from the base station through an antenna 121 connected to a receiver 122. A carrier frequency of the selected RF receiver is generated by a reception frequency synthesizer 123 and supplied to a receiver. RF demodulator 124 that demodulates the received carrier signal in an intermediate frequency (IF) signal. The signal I F is demodulated additionally by a modulator I F 125 which retrieves the original digital information before modulation p / 4 DQPSK. The digital information is then passed to the equalizer 1 13 which formats the information into two-bit symbols, and then to a symbol detector 126 which converts the symbols into a single-bit data stream that includes the voice or FACCH data and the SACCH data. The symbol detector 126 distributes the FACCH or voice data to a module-2 addend 127, and the SACCH burst deinterleter data-22 135.

The module-2 addiver 127 is connected to the encryption unit 1 15 and is used to decrypt the encrypted voice or FACCH data by subtracting, on a bit-by-bit basis, the same pseudo random key current used by the transmitter in the base station to encrypt the data. The deciphered output of the module-2 addiver 127 is fed to a burst deinterleaver-2 that reconstructs the voice or FACCH data by assembling the bits from two consecutive digital data structures. The burst deinterleaver-2 128 is coupled to two channel decoders 129 and 130 which decode convolutionally coded voice or FACCH data, respectively and check the CRC bits to determine if an error has occurred (the CRC bits also provide a method to distinguish voice data from FACCH data). The voice data is fed from the channel decoder 129 to a decoder 131 that retrieves the original digital speech signal. The signal is converted to analog and filtered before transmission through a loudspeaker 133. Any FACCH messages are detected by a FACCH detector 132 and transmitted to a microprocessor 134 for appropriate action. With continuous reference to FIG. 4, the burst deinterleaver-2 2 135 reassembles the SACCH data which is distributed over 22 consecutive structures. The output of the burst deinterleaver-22 135 is provided as input to a channel decoder 136. Any SACCH messages are detected by an SACCH detector 137 and transferred to the microprocessor 134 for appropriate action. The microprocessor 134 controls the activities of the wireless terminal 400 and the communications between the wireless thermometer 400 and the base stations. The decisions are made by the microprocessor 134 in accordance with the messages received from a base station and the measurements executed by the wireless terminal 400. The microprocessor 134 is provided with a memory (not shown) and is also connected to a keyboard input. of terminal and screen output unit 138. The keyboard and display unit 138 allow the user to initiate and answer the calls and record the information in the memory of the wireless terminal.

It should be noted that most of the components of the wireless terminal shown in Figure 4 can be used to construct a base station 600 as shown in Figure 6, in which like components are designated with the same reference numbers in FIG. 4 and are additionally designated by means of a (') to distinguish the base station components from the components of the wireless terminal. The base station 600 of FIG. 6 communicates with the wireless terminal 400 of FIG. 4 using a segment format as shown in FIG. 7, which is similar to the segment format used by the wireless terminal, as shown in FIG. Figure 5. As will be appreciated by persons with ordinary skill in the art, there may be certain differences in the construction of the base station and the wireless terminal. For example, as shown in Figure 6, the base station may not only one but two receiver antennas 121 'and the associated radio hardware 122' 125 'for diversity reception. In addition, since the base station supports three digital (total speed) traffic channels (DTCHs) per RF channel as shown in Figure 2, the baseband processing hardware can be tripled at the base station and the demodulator I F125 can not only one but three outputs, one for each of the three digital traffic channels. In addition, since the base station usually operates on multiple RF channels, it can include multiple sets of radio channel hardware (baseband and radio processing hardware) as well as a programmable frequency combiner 1 18a 'to perform the selection of the RF channels that will be used by the radio station in accordance with the applicable cellular frequency reuse plan. On the other hand, the base station may not include a user keyboard and a display unit 138, although it may include a signal level meter 100 'to measure the resistance of the signal received by each of the two antennas 121' and to provide an output to the microprocessor 134 '(for transfer purposes). Other differences between the wireless terminal 400 and the base station will be readily apparent to those skilled in the art. The wireless terminal 400 of Figure 4 and the base station 600 of Figure 6 are capable of operating on a digital traffic channel (DTCH), although they can also be easily configured to operate on a digital control channel (DCC H) if, for example, the length and format of a DCCH segment are made compatible with those specified for the DTCH segment in IS-136 as suggested in U.S. Patent 5,404, 355 cited above. Figure 4 shows additional components that, for example, can be used to decode messages transmitted over a Paging Channel (PCH) or the DCCH in accordance with the aspects of the present invention. Although PCH messages, such as the FACCH and SACCH messages, are interleaved to protect against errors induced by the radio channel, the interleaving of the PCH messages is limited within a segment (intra-segment interleaving) since, for purposes of inactive mode efficiency, the wireless terminal must not be aware of more than one PCH segment. As shown in Figure 4, after demodulation and equalization, the page messages are deinterleaved in a burst deinterleaver-1 139 before channel decoding in a channel decoder 140 and detection in a PCH 141 detector. Any page messages are transferred from the detector PCH 141 is the microprocessor 134 for analysis of action, as will be described in detail below. For purposes of the description herein, although a DCCH format that is compatible with the IS-136 DCCH form may be used, in general any DCCH format or for that matter, the interleaving method may be used such as, for example, the format DCCH and the interleaving method specified in the GSM standard. In addition, the DCCH can be implemented using different transmission techniques or in combination with time division multiplexing (TDM) such as, for example, code division multiplexing. The operation and the paging channel according to industrial or governmental standards (for example IS-95 and IS-136 in the United States of America, GSM in Europe and PDC in Japan) is illustrated in Figure 8. Referring to Figure 8, most of these standards provide for the construction of a page message (before the error correction and interleaving coding) as an "L2" (L2) structure of data 200 that contains an L2 201 header, a "Layer 3" message data payload (L3) 202 and an error detection code such as a cyclic redundancy check code with the final bits of 203 (the final bits are generally used with convolutional coding and usually they are set to zero). The header 201 includes in supplementary training for the handling of radio resources (for example actions that are to be taken by the receiver) or for other purposes, and may also include an indication of the type or length of the L3 voice data in the payload 202 (for example, a bit may be assigned in header 201 to indicate an empty page message in payload 202). For an empty page, the payload 202 includes a predetermined value that is defined by the applicable standard (for example, all zero in IS-136). For a non-empty page, the payload 202 includes a mobile station identifier (MSI D) and possibly, auxiliary data such as an indication of the type of calls (ie voice, data, etc.). The header 201 and the payload 202 are encoded with the CRC code 203 for error detection purposes. Prior to transmission on the PCH, the structure 202 is encoded with an error correction code and the encoded data is interleaved on one or more segments according to the specification of the applicable standard. In the receiver (for example, the wireless terminal), the received segment (s) are first demodulated and possibly, equalized. Following this follows the de-interleaving of the demodulated (and possibly equalized) data and the channel decoding of the deinterleaved data. The wireless terminal also verifies the residual errors by calculating CRC using the de-interleaved and decoded data (i.e., received header 201 and payload 202) and comparing the CRC with the received CRC (i.e. received C RC 203). If the CRC comparison indicates that the data was received correctly, the wireless terminal checks the received header 201 to determine whether or not an action is required, and whether the message is an empty page or not. If no action is required and the message is an empty page, the wireless terminal can return to idle mode. If a certain action is required, the wireless terminal takes the required action. Also, if the page is not an empty page (ie it is a non-empty page), the wireless terminal compares the received MSI D with its own MSI D which is stored in the memory. If you couple the MSI D, the wireless terminal sends a page response to the system. However, if the MSI D do not dock (that is, the page is for another wireless terminal, the wireless terminal can return to the idle mode) As shown in Figure 10, the downlink segment DCCH includes a feedback field of shared channel (SCF) that contains the information to support the random access scheme on the downlink. The downlink segment further includes a coded superstructure phase (CSFP) field that contains information to assist the wireless terminal in searching for the start of the superstructure in the DCCH. Another notable difference between the DCCH and DTCH segment formats is the absence of the intersegment interleaving on the DCCH to facilitate the operation of the idle mode. Figure 1 1 A illustrates the structure framework of the DCCH (downlink) in accordance with IS-136, the DCCH segments are mapped into logical channels that are organized into a series of superstructures (note that IS-136 currently specifies that there is no special structure frame for the downlink DCCH, since all the time segments on the uplink can be used for system access via the wireless terminal). A full-speed DCCH would occupy 2 of the 6 segments of an IS-136 TDMA structure as shown in Figure 11A. The logical channels specified in IS-136 include a transmission control channel (BCCH) to carry information related to the system that is transmitted to all wireless terminals, and a short message service, paging and access response channel ( SPACH) to transport the information that is sent to specific wireless terminals. The structure and operation of BCCH and SPACH is described in more detail below. For an efficient idle mode operation with rapid acquisition in cell selection (ie, DCCH), the BCCH is divided into logical subchannels as taught in the aforementioned U.S. Patent No. 5,404,355. As shown in Figure 11A, the BCCH includes a BCCH (F-BCCH), an extended BCCH (E-BCCH), and a point-to-multipoint short message service BCCH (S-BCCH). The F-BCCH is used to transmit the DCCH structure parameters and other parameters required for access to the system. The E-BCCH is used to transmit information that is not critical in terms of time (for the operation of wireless terminals) as the information in the F-BCCH. The S-BCCH is used for the transmission of the short message service (SMS). SPACH is also divided into logical subchannels, which include a short point-to-point message service channel (SMSCH), a paging channel (PCH) and an access response channel (ARCH) (not shown in Figures 11A). The SMSCH is used to transport user messages to a specific wireless terminal. The PCH is used to transport paging messages to different wireless terminals. The ARCH is used to respond to access requests from one of the wireless terminals, for example, by supplying a channel assignment message to that wireless terminal. The F-BCCH and E-BCCH allow the system to transmit different types of supplementary information at different speeds depending on their importance for the proper operation of the wireless terminals. The information that defines the configuration of the systems and the rules for access to the system through the wireless terminals is transmitted in the F-BCCH. Since this information is preferably transmitted, at a rate that allows wireless terminals to quickly access the system, a complete set of this information is typically sent on the F-BCC H once per superstructure. The less critical supplementary information may be transmitted at a lower speed in the E-BCCH. A complete set of information E-BCCH can cover several superstructure. The S-BCCH on the other hand, allows the system to decouple the transmission of supplementary information from the SMS transmission by providing a dedicated channel for SMS messages. To decouple the requirement for reading periodicity of the supplementary information through the wireless terminal (for example, for purposes of efficient operation of the inactive mode), starting from the periodicity requirement of the BCCH transmission through the system (for purposes of rapid acquisition in the selection of cells), each of the sub-channels F-BCC H and E-BCCH is associated with a change signal in another logical sub-channel. A change signal indicates when the corresponding BCCH information has changed. For example, changes in F-BCC H are indicated by a change signal in the PCH and changes in the E-BCCH are indicated by a change signal in the F-BCCH.

The exchange signals allow the wireless terminal to avoid re-reading the BCCH information that has not changed, thereby allowing the wireless station to reduce battery drainage, as taught in the aforementioned United States Patent No. 5,404, 355. The wireless terminal first gives the BCCH information required when acquiring the DCCH. However, subsequently the wireless terminal will only read the BCCH Information and may remain in the idle mode when there are no changes in the BCCH information. This allows efficient operation in the idle mode (ie, lower periodicity of BCCH information reading), and at the same time, rapid acquisition in the selection of cells (ie, higher BCCH transmission periodicity). With continuous reference to Figure 1 1 A, an SF superstructure is defined in IS-136 as a collection of 32 consecutive time segments (640 ms) for a full speed DCCH (or 16 medium speed DCCH segments), starting with the first BCCH segment. The first segments of the superstructure are assigned to F. BCCH and the remaining segments are assigned to E-BCC H; S-BCCH and SPACH. A wireless terminal determines from the information in the F-BCCH segment (s) at the beginning of the superstructure which of the others of the superstructure are assigned to E-BCCH, S-BCC HY SPAC H, As shown in Figure 1 1A, each of the subchannels BCCH (F-BCCH, E-BCCH and S.BCCH) is assigned with an integer number of the time segments DCCH in each repeating superstructure. The other segments in the superstructure are assigned to the SPACH subchannels (SMSCH, PCH and ARCH) on a fully dynamic basis. For this reason, the segments available in each superstructure for SMSCH, PCH and ARCH are generically shown as SPACH in Figure 11 A. A wireless terminal identifies the use of an SPACH segment (ie SMSCH, PCH or ARCH) from the header information L2). IS-136 specifies three forms of mobile station identity (MSID) that can be used for the paging of a wireless terminal: the mobile identification number (MIN), the international mobile station identity (IMS I), the station identity temporary mobile (TMSI). The MIN draws its roots towards the EIA / TIA 553 and IS-54 standards (previously described) and is a digital representation of the wireless terminal directory number according to the telephone numbering plan in North America. The IMSI is used for international monitoring and includes a country code that identifies the country of origin of the wireless terminal and other information to identify its national system (for billing purposes and others). The TMSI is assigned to a wireless terminal on a temporary basis within a specific area (for example, the service area of an MSC or a location area in this service area) and the wireless terminal is usually reassigned to another TMSI after of a predetermined period or when the wireless terminal moves out of this area. The main benefit of the use of the TMSI is the increased paging capacity, since TMSI usually contains fewer bits than the MIN or IMSI and, therefore, more pages can be transported in a PCH segment. Depending on the allocation procedures for the TMSI, it may be increased to provide another benefit of the confidentiality of the user's identity. A wireless terminal according to IS-136 can be assigned with a MIN, an IMSI or both a MIN and an IMSI. The MIN and / or IMSI are referred to as the permanent mobile station (PMSID) identity in IS-136. A wireless terminal that has a MIN and an IMSI will only use one or the other with its PMSID, determined by the BCCH data as specified in the ISD-136 standard. However, the wireless terminal can use both as a PMSID (either MIN or IMSI) and a TMSI, at different times. At any given time, the wireless terminal uses one or the other of the PMSID and TMSI. The wireless terminal will usually monitor your PCH segment for your PMSID. If a TMSI is assigned to the wireless terminal, the wireless terminal will then monitor the PCH segment only for the TMSI. The TMSI assignment may expire and if a new TMSI is not assigned the wireless terminal reverts to the use of PMSID when communicating with the system. In IS-136, an identity type field (I DT) may be included in structure L2 to inform the wireless terminal which identity it is using in the page message. The I DT field may not be included in the L2 structure if the identity type is implicit from the structure type. Other standards may require a wireless terminal to monitor PCH for both PMSI D and TMSI. According to IS-136, all pages (whether containing PMSI D or TMSI) are repeated in the corresponding time segments in the following superstructure to increase the probability that a mobile station receives a page and even for radio conditions severe If and only if the mobile station can not decode the PCH segment in the first superstructure ("primary"), the corresponding PC H segment in the second ("secondary") superstructure will be read (the primary and secondary superstructures are collectively referred to as a "hyperstructure"). Figure 1 1 B shows the format of the hyperstructure, including the F-BCCH F, E-BCCH E, S-BCCH S and the reserved channel R. Under normal operating conditions, the mobile station will have to read only one segment per hyperstructure, which improves efficiency inactive. Each mobile station is assigned with one of eight different kinds of paging structure (PFCs) that define how often the mobile station reads its PCH segment (ie, each nth hyperstructure, where n is 1, 2, 3, 6 , 12, 24, 48 or 96, provided for the "inactive time" from 1.28 to 123 seconds). Analogous to the structure surface (SFP), a hyperstructure counter (HCF) is provided in order for the mobile station to synchronize the assigned hyperstructure. Examples of primary allocation PCH (P) and secondary PCH (S) for various paging structure classes PFCi, PFC2, PCF3, PFC4, which are aligned to HFC = 0 are shown in Figure 11C. For PFC greater than 1, alignment with any HFC value is possible. A mobile station can be reassigned to a different PFC to optimize the transfer between inactive mode efficiency and call set-up delay, with lower PFC that implies a shorter idle time and a call set-up delay as a higher PFC it implies a longer idle time and call set-up delay. Once the mobile station has read the BCCH (for example, on power up), it determines which PCH segment to monitor based on its permanent mobile station identity (PMSID), and then enters the idle mode until it receives that segment with or BCCH information changes. More than one PCH can be defined in a superstructure that each PCH occupies a segment. If the system is overloaded (during business hours) with pages for a PCH segment, the mobile station may also be required to read another PCH segment (for example another segment in the same superstructure) as specified in the standard. It can be seen that although a conventional mobile station compatible with IS-136 will typically "be alert" to read its PCH segment each nth hyperstructure as determined by its PFC, the PCH segment at any nth hyperstructure can be "captured" for use by another SPACH subchannel, since the segments are signaled to SPACH subchannels on a dynamic basis and according to capacity requirements. Until the deinterleaving and decoding of L2 header information in the SPACH segment, the mobile station typically can not determine whether the SPACH segment is a PCH, an ARCH or an SMASCH. IS-136, like other standards, uses a layered approach to the transmission of messages over the DCCH. Figure 12 shows how a "Layer 3" (L3) message (for example, a page message) is transferred into one or more "Layer 2" (L2) structures that are then mapped to a physical layer segment " Layer 1"(L1). The L3 message is analyzed in as many L2 structures as necessary under the applicable protocol (different protocols are specified for BCCH and SPACH). Each structure L2 includes L3 data and supplementary information for the operation of the L2 protocol. Each L2 structure is mapped to an individual L1 segment through the addition of the error coding (CRC and final bits) and the supplementary information (header) specified for the physical layer operation. For all I S-136 DCCH subchannels, operation L2 has been defined to be aligned with operation L1 such that a protocol structure L2 is transported within an individual underlying physical layer segment. Therefore, all bits of any L2 structure are in vias within a time segment (ie, only intra-segment interleaving is executed after channel coding and before transmission.) IS-136 specifies different L2 structure formats for different types of L3 messages Two illustrative L2 structure formats for SPACH messages are shown in Figures 13-14. Figure 13 shows a "null structure" which is sent when no other information needs to be transmitted in a given SPACH burst, for example, when an empty page message is transmitted in the PCH, while figure 14 shows a "permanent triple page structure" which is used to transmit a non-empty page message containing up to three 34-bit MI Ns (IS-136 also specifies some different paging structures, although Figure 4 is illustrative for purposes of the present invention). structures in figures 13-14 begin with a heading A (SPACH) and term inan with a CRC. In addition to the A header, the null structure of Figure 13 contains a one-bit "pass" field and fill data (for example, all are zeros). The GA field indicates whether the DCCH is excluded (for example due to failure, maintenance, etc.) to activate the new selection of the DCCH (ie, the value "0" means that the DCCH is not excluded while the value "1"). "indicates that DCC H is excluded. The permanent triple page structure of Figure 14, on the other hand, contains MSI Ds, MSI D1,, MSI D2, MSI D3 (in this case, M I N s) for up to three different mobile stations. Referring now to Figure 15, header A 300 includes a 3-bit burst usage field (BU) 302, a 1-bit PCH continuation field (PCON) 304, a 1-bit-BCCH notification field of field (BCN) 306, a 1-bit paging structure modifier field (PFM) 308 and a field notification S-BCCH field (S-BCN) of 1 bit 310. The BU 302 field identifies the structure type L2 (for example, the value "000" designates a null structure as shown in Figure 13 while the value "101" designates a permanent triple page structure as shown in Figure 14). The PCON field 304 informs the mobile station whether another segment S-PC H should also read the current superstructure (for example, the value "1" designates the continuous reading PCH). Field BCN 306 and field S-BCN 310 alternate (between one and zero) whenever there is a change in the information F-BCCH or E-BCCH. The PFM field 308 informs the mobile station whether it should modify its paging structure class operation (PFC), ie the value "0" which indicates that the mobile station must use allocated PFC while the value "1"indicates that you must use the PFC that is one greater or one lower than your assigned PFC, as indicated by the information sent in the BCCH. IS-136 also specifies some other headers that are used in other types of SPACH L2 structures, although Figure 15 is illustrative for purposes of the present invention. For this reason, in accordance with the structure format IS-136 illustrated in Figures 13-15, a message of empty pages (null structure) is not necessarily lacking information, as is the supplementary L2 (ie, header A and gauge field GA) that can actually contain information without padding about activities that must be executed by the mobile station.

A Cana l Paging Attribute Descriptor (PAD) The present invention arises from the embodiment that a paging attribute descriptor (PAD) channel can be provided (for example for a system such as the I-136 system described above) that can be decoded relatively quickly by a mobile station to allow a mobile station (or other type of wireless station) to avoid unnecessary processing of paging channel information (PCH). In particular, the PAD channel can be used to reduce the need to completely decode "empty" PCH messages or PCH messages directed to other stations. In accordance with the embodiments of the present invention, a PAD channel message is carried in reserved bits in the DCCH segment described in FIG. 15. In one embodiment, a PAD channel message is communicated in three reserved bits in the CSFD field. In another embodiment, a PAD channel message for a particular PCH message is carried in reserved bits at the end of the preceding DCCH segment. In other embodiments, the PAD channel includes a combination of the reserved bits mentioned above. Even in other embodiments, the PAD channel incorporates a change signal that is used to indicate whether the control information such as the supplementary information L2 described above has changed, necessitating the reading of a page message or other actions . For the IS-136 system described above, there are 5 reserved bits in a physical layer DCCH segment. The oldest mobile stations are typically designated to not have a assumption about the values of those bits, that is they are • ignored. Three of these reserved bits are in the CSFD field. The recovery of these bits can be aided by the 4 bits of redundancy in the code (12, 8) used to encode the CSFP field, as the superstructure phase is known for a mobile station when it enters inactive mode. A decoding process that takes advantage of the known SFP value is described in U.S. Patent No. 5,751,731 to Raith, the description of which is incorporated in • its entirety to the present. Knowing the SFP, the code (12, 8) is effectively converts into a code (7, 3) which has 8 code words. The remaining 2 reserved bits are at the end of the DCCH time segment, just before the SYNC field of the next time segment. In order to reduce to the minimum the time for which a receiver has to read the data, the reserved bits of the time segments can be associated with the successive time segment to provide a PAD channel for the successive time segment. In accordance with any aspect of the present invention a PAD channel is provided while maintaining the ability to monitor supplementary information L2. In a conventional IS-136 mobile station, the mobile station typically needs to verify the CRC in order to correctly detect (verify) the supplementary information L2. However, because the CRC is based on the supplementary data and the payload (L3 data), the correct detection of the supplementary information L2 would generally require that the • mobile station will decode the entire structure L2 in order to verify the C RC. If this is done routinely, it would vitiate the potential energy savings from a timely detection and disposal of an empty page. On the other hand, if the mobile station detects a empty page as described before, therefore, it does not read and verify the supplementary information L2 in the null structure, it may fail to take the necessary actions.

• For some supplementary information L2 specified in IS-136, the mobile station has multiple opportunities to read the information. For example, if the BCN bit has been alternated in the current superstructure to indicate that the BCCH information has changed, even if the mobile station does not read the header L2, it will lose the opportunity to update the BCCH information during the next superstructure. However, since the system maintains Generally the BCN as its new value for several superstructures, it may be sufficient for the mobile station to periodically decode (eg, every 5th superstructure) the entire PCH segment (even if it is transporting an empty page) in order to read the header L2. In other cases, the mobile station may process the page messages according to the present invention. A potential disadvantage of this solution is when the system, for example, toggles the BCN bit in two consecutive superstructures and the mobile station reads the second (or subsequent) superstructure. In this case, the mobile station will not update the BCCH information since the change notification should have been returned to its original value after two consecutive alternations. However, it is considered that such instances will be rare in practice for two reasons. First, to ensure that a mobile station is alerted to changes in the BCCH information, existing systems usually do not alternate the BCN in two consecutive superstructures due to the possibility that a mobile station may lose reading of the PCH segment in the first superstructure due to channel errors. Secondly, the ad hoc administration of the BCCH requires that the frequency of changes in the BCCH information is not greater than the lower reading frequency of the PCH segment according to the upper PFC of the mobile stations operating in the system (so that even the mobile stations assigned to the larger PFC will be able to keep up with the changes in the BCCH information). In summary, for the purposes of detecting the BCN on a noisy channel, the solution of the complete decoding of the PCH segment at regular intervals should be very effective in practice. Other header information L2 (for example, PCON), valid only for the current L2 structure. For a mobile station to act appropriately, preferably it does not lose an individual instantaneous value of said field. However, some of these instant information may be activated under circumstances that would generally lead the mobile station to automatically read this information by applying the detection techniques of the present invention. In these circumstances, there is no need to explicitly detect the information element. For example, according to IS-136, the PCON bit is activated whenever one or more pages that must be sent by the system can not be accommodated in the current PCH segment because it contains the maximum number of MSIDs (for example, 5 MSIDs). must be sent and the system is using the structure L2 shown in Figure 14) or a "soft" page (ie, a page for an individual mobile station with the rest of the segment that is used to convey a user message to that station mobile) . In any case, structure L2 in the PCH segment by definition will contain at least one MSI D and possibly some user data. Therefore, if the mobile station is informed that the assigned PCH is transporting a non-empty page, the mobile station will process the PCH and read the supplementary data L2 including PCON. In summary, it is desirable that a mobile station capable of PAD perform the following 7 tasks while reducing the frequency at which PCH messages are fully decoded: 1. executing tasks associated with the link quality meter monitor. radio (MRLQ); 2. determine whether the PCON signal is enabled or not; 3. determine whether the GA signal is enabled or not; 4. determine whether the BCN signal is alternating or not; 5. determine whether the S-BCN signal is alternating or not; 6. determine if the PFM signal is alternated or not; 7. Determine if the mobile station is paged. The monitor radio link quality (MRLQ) counter is used to determine whether the quality of the radio link reception is good enough to correctly process the received data and conduct the subsequent call activity. If quality is considered scarce, the mobile station can enter a new cell selection procedure in which it can select another DCCH, most likely another one transmitted from another base station. The MRLQ counter is commonly initialized to a value of 10 when in standby in a DCCH. For each L2 CRC check not successful while reading the PCH assigned to the mobile station, the MRLQ counter is decremented. For each successful CRC check, the MRLQ counter is incremented, with the value of the MRLQ counter that is commonly restricted so that it never has a value greater than 10. If the value of the M RLQ counter is set to zero, a malfunction is typically declared. radio link, causing the mobile station to start a search for a better quality DCCH. In accordance with one aspect of the present invention, the existing M RLQ procedure is modified. The L2 CRC verification can be replaced with a derived quality estimate from the data retrieved from the PAD channel. For example, the quality estimate may be based on the success in decoding a received CSFP field in which the PAD channel is transported according to the Hamming code (12, 8) associated with the CSFP field. This code can detect simple bit errors and some double bit errors. If a Hamming decoding error (12, 8) is detected, the M RLQ can be decreased. However, the smaller code (12, 8) generally does not have the same sensitivity to the radio link quality as the L2 C RC check. If the code (12, 8) is more sensitive to bit errors, the mobile station can use two counters, for example, an M RLQ-1 counter and an M R LQ-2 counter. The counter M RLQ-1 can be operated for IS-136. The counter M R LQ-2 can be operated by the result of decoding the code (12, 8). The M RQ L-2 may be preset to a different value of MR LQ-1, such as 15. However, for an extremely bad band DCCH, for example, when a mobile station enters an area with a very good reception quality. bad, can no longer take to nmc station to declare a radio link failure. In order to maintain the existing MRLQ counter properties while allowing the mobile station not to process the PCH L2 structure more frequently, the MRLQ-2 can be set to a smaller value and, as long as the counter reaches 0, the mobile station it may require the reading of PC H and set the MRLQ-1 to a value between 0 and 10. If the counter M RLQ-1 reaches zero, a radio link failure is declared. If the counter M R LQ-1 reaches a value higher than the initial value, for example 8 or 10, the mobile station can be allowed to back off only by reading the PAD channel, now set the M RLQ-2 to its initial value again. The pass signal (GA) is enabled to indicate to the mobile stations that service is not provided by the system. An example of this instance is when the system is disabled for repair or miodification. The activation of the GA signal is a very rare event. The PCON signal can be enabled by the system when it has more pages to be supplied to a paging group than what the associated paging segment can carry. The mobile station, which was not paged in this segment, will read one or more additional paging segments before the nominal paging segment occurs again. When the PFM signal is enabled, the mobile station must increase or decrease (as specified by the data in the BCCH) the paging structure class with respect to the default paging structure class. The PFM bit will only be enabled most likely a few times a day. The PCON signal must be detected during the reception of the page segment in which it was set. However, the BCN, S-BCN, GA and PFM signals will typically maintain their values for multiple paging structures, ie multiple PCH readings. So, the mobile station typically has multiple opportunities to read the BCN, S-BCN, GA and PFM signals. In order not to lose the activation of the PCON signal, it can be included in the PAD channel. It is also possible to map multiple control fields, for example, the control signal and other control fields, to a single signal or value in the PAD channel without any significant increase in page message readings to (PCH). Therefore, if any of the multiplexed signals is enabled, the PAD will indicate that the PCH reading is required. The combined indication can also be mapped to a general value or bit that requests every mobile station to read the PCH. The BCN and S-BCN signals (or representations thereof) may be included separately or combined in a similar manner with an individual signal or value in the PAD channel. Because the BCN and S-BCN signals typically maintain their values for extended periods, the rendering signals may be sent less frequently than the paging structure, i.e., the PCH reading frequency. Therefore, these signals can be multiplexed by time in an individual signal in the PAD channel. For example, an individual signal field in the PAD channel may be used to alternatively represent the BCN signals and the S-BCN signals in successive instances of the PAD. More than two signals can also be multiplexed by time in this way. For example, the PFM signal can be combined with the BC N signal or a combined BCN / S-BCN signal. In another example, the GA signal can be combined with the PFM signal. A few illustrative PAD channel coding schemes will now be described with reference to tables 1-8, in particular, coding schemes using 3-bit codes as they should be employed in a PAD channel implemented in the reserved bits of the CSFP field of a PCH message. As described below, the particular coding of the PAD channel may a predetermined system convention, or may be transmitted for each mobile station to registration, activation or the like. Referring to Table 1, in a first mode, the PAD channel is coded to differentiate between groups of mobile stations. A value "000" is interpreted as representing that a PCH message does not require reading from a mobile station, and a value "001" is interpreted as "all mobile stations must read PCH". The respective values "001! -" 1 10"are assigned to some of the 6 groups (6), with a mobile station that is assigned to one or more of the groups • This refined differentiation allows mobile stations to avoid reading of the PCH with a PCH reading speed reduction that corresponds to the number of groups in the PAD channel.

Mobile stations can be assigned according to several types of groupings. These grouping groups include: (1) Grouping by value M I N I MS I; (2) grouping by predetermined attributes that are not based on the M I N / I MS I value; and (3) grouping according to the group assignments sent to the mobile stations. For the first type of grouping, the mobile station and the system do not need to exchange additional data to establish a common understanding of what the system should activate in a PCH reading for a particular mobile station. An extension or modification of the existing formula that the system and the mobile station use to establish a particular PCH segment in the superstructure can be used. In cases where one or more stations in the same group are paged, the system sets the PA D channel value for the corresponding value in this group. If the mobile stations from multiple groups are paged and in a particular PCH message, the PAD value can be set for the value "all mobile station must read PCH". The illustrative attributes that could be used for the second • type of grouping include, but are not limited to assigned PFC 5, type of communication (eg, packet, voice, or SMS data), electronic serial number (ESN), and address form used (eg MI N , IMSI, TMSI20, TMSI24), For example, a plurality of mobile stations having different PFC's, for example, PFC1, PFC2, PC3 ... PFC8, can be assigned to Monitor a particular PCH segment based on its PFC. The value • PAD channel for a particular PCH message transmitted in this segment, can be used to instruct a particular PFC to completely decode the PCH message. Thus, as an example, a mobile station PFC 1 that reads a PCH segment in each The hyperstructure can be instructed to decode a particular PCH message so that a PFC2 mobile station assigned to monitor the same PCH segment will not be instructed to read the particular PCH message. The second attribute can be used to differentiate the mobile stations according to capacity. For example, if a PAD channel message indicates an incoming packet data transaction and a mobile station is not equipped with such a capability, the mobile station can interpret the PCH message as directed to another mobile station, and prevents further processing of the message.

PCH message.

The third attribute described above assigns PAD channel values based on a function to the electronic serial number (ESN) For example, the PAD channel may contain the two least bits • Important ESNs, which can be used to identify 4 different groups. The fourth attribute described above differentiates the mobile stations based on the type of address of the use of mobile stations. A mobile station that adheres to IS-136 is allowed to ignore all other address forms than the "agreed" form of address according to the combination of the BCCH data and the • record response message. Therefore, if the PAD channel indicates that the address form used in a particular PCH message is M I N and a mobile station is enabled to read TMS 120, the mobile station can ignore the particular PCH message. Note 15 that a particular PCH message may contain only one address form. The illustrative techniques for sending the stream, or more specifically the values of the PAD channel that should cause the mobile station to read the PCH, according to the third type of cluster includes: (1) sending a PAD value assigned to a particular mobile station in a registration response sent to the mobile station; (2) sending a PAD value to a mobile station as part of an air-to-air activation teleservice (OATS) in which the mobile station is enabled to communicate in a system; and (3) sending PAD encoding rules in the message it transmits on a transmission channel (for example BCC H). For the first two types of communication of the PA value assignments D, a PAD value assignment for a particular mobile station is sent to the mobile station in a message sent specifically to that mobile station. For example, the value "1 1 1" ("reading required for all mobile stations") and another value can be sent to the mobile station and the mobile station does not need to be informed about the other values, for example, the value for "no mobile station is required to read." Alternatively, the PAD information message is sent to a mobile station can indicate which of the predefined encoding rules applies, for example, any of the encoding rules described in tables 1 -8, assuming that the mobile station has prior knowledge. existing of those rules. This method, the specific mobile station and the specific time group assignment, allows the system to assign the mobile stations in any type of grouping, for example, to ensure the equitable distribution of the mobile station currently connected to the available groups. Each time the mobile station executes a record "on a time basis" the system can reassign the mobile station to another group (new PAD values). With a predefined grouping, for example, based on M I N / I MSI, the distribution becomes a statistical process based on which particular mobile stations are currently connected with which the system can not be modified.

For the third example, the data transmitted on a transmission channel can indicate which predefined coding rules apply as described above and the information for the mobile stations to determine the PAD values of interest. If the mobile station finds a non-recognizable encoding rule (number of rules), the mobile station can ignore the PAD channel and process the 7 tasks previously identified by the prior art. Table 2 shows an implementation that combines several grouping criteria of type of "attribute". In particular, Table 2 illustrates a grouping of attribute type based on (1) default attributes that are not based on a MIN / IMSI value, (2) assigned PFC and (3) address form used.

Table 3 shows an example in which four groups are defined, and in which the particular PAD channel values can be used to instruct the terminals from the selected combinations of those groups to decode a PCH message. Groups can be defined using any of the criteria described above. This type of PAD channel value assignment can advantageously be used in a PCH message containing pages for mobile stations from more than one group, since it allows multiple groups to be instructed to read the PCH message without requiring all groups to read. the message.

Table 4 shows a similar coding, except that here the PAD channel is able to differentiate between all the combinations of two possible groups of a set of groups. This coding allows several groups to have three bits in the PAD channel, so that each group is assigned one bit in the PAD channel. The coding can be visualized as a bit map, where each group is indicated by a bit in the PAD channel.

The examples illustrated in Tables 1-4 do not specifically provide signals (eg BCN) related to the supplementary information L2, as described above with reference to Figure 15. In those embodiments, a separate field for change signals may be provided. (for example, in the two reserved bits at the end of the preceding DCCH segment, as described above) or the system can transmit a value "all mobile stations should read" in the PAD channel for a predetermined number of successive PCH segments in order to to allow mobile stations to detect alternating change signals or specific PCH messages containing a momentary signal (eg PCON).

In Table 5, one bit of the PAD channel is assigned as a change signal. Multiple "real" signals may have been mapped within this individual signal, for example, the NCBs and S-BCN. The other two bits are assigned to a group, each one, that is to say a bit map. The example shown in Table 6 differs from Example 5 in that two bits of the PAD channel are assigned as change signals (eg, BCN / PFM and S-BCCH). In Table 7, one bit in the PAD channel is assigned to the PCON signal and the two remaining bits are mapped per bit for two groups. The coding in Table 8 is designed to be firm against erroneous decisions due to bit errors in decoding the PAD channel. Although the code (12.8) can correct a simple bit error in the 12-bit CSFP field, it may result in unsatisfactory performance. The coding of the PAD channel effectively includes a code (3,1), that is, an information bit sent in three bits. Any individual bit error remaining from the decoding of the code (12.8) can be corrected by the code (3.1), for example, the decoded value "010" will be interpreted as "000".

Table 6 Value Function 00 Change signals = 0.0, reading is not required 01 Change signals = 0.0, all mobile stations must be read 10 Signals of change = 0.1, reading is not required 11 Signals of change = 0.1, all mobile stations must be read 00 Signals of change = 1.0, reading is not required 01 Signals of change = 1.0, all mobile stations must be read 10 Signals of change = 1.1, not required reading 11 Signals of change = 1.1, all mobile stations must be read As described earlier in IS-136, there are two reserved bits in a DCCH segment (see figure 10). In one embodiment of the present invention, the two reserved bits can be assigned to the BCN signals and the S-BCN signals instead of being included in a PA D in the CSFP field. The time multiplexing of both signals in one of the reserved bits is also possible. As the reserved bits are at the end of the time segment, it may be advantageous to associate the reserved bits in a first segment with the PCH message in a second successive segment, so that the mobile station processes as small a quantity of data as possible. . Therefore, after the mobile station acquires synchronization by time with the help of the SYNC of the second segment, it can read the two previous received bits of the first segment to determine the status of the signals. In summary, the 7 tasks described above can be achieved in accordance with the present invention without requiring the mobile station to read each channel message PCH. By including alternating signals in the PAD channel or in the fields outside the PAD channel but associated with it, the channel quality and status indicators described above can be monitored without completely decoding the PCH messages. It should be noted that the PAD channel can be displayed including the CSFP and reserved bits at the end of the DCCH segment, even if those bits are temporarily separated. In order to minimize the time required for the mobile station to remain "alert", it is preferable that the PAD channel be placed near the presented SYNC. However, in order to serve both the previous and new stations (backward compatibility) it is preferable to use the reserved reserved fields for the PAD channel. If the capacity penalty of having a system that supports two different DCCH formats is acceptable, or for a complete new system, optimal coding and placement for the PAD channel can be selected. If the presented PAD is not located near the SYNC field it may be possible, especially for a good radio channel condition, to bypass the acquisition of time synchronization and instead execute the "blind synchronization" of the data around the PAD channel field. Although the use of the reserved bits in the CSFP presented for the PAD channel allows backward compatibility, the location of the presented CSFP is very far from the synchronization word, which may require that the mobile station decode approximately half of the PCH segment before I can retrieve the PAD channel message. according to another embodiment of the present invention, the PAD channel uses the two reserved bits in the segment just before a PCH segment for the PAD channel associated with the PCH segment. As described above, due to the proximity of those bits with the SYNC field of the PCH segment, it uses those two segments for the PAD channel that allows the mobile station to reduce the amount of processing necessary to acquire the PAD channel, compared to a channel PAD transported in the CSFP field of the PCH segment. After acquiring time and channel synchronization, the base station can immediately read the two bits before the SYNC field without requiring additional coding of the PCH segment. The coding for said PAD channel could be, for example, "00" for "without PCH reading" and "11" for "reading of all mobile stations is required". Any additional assignment of the functions of the two bits can make the PAD channel very unreliable. However, even using two-bit codes for the two values may be insufficient. Mobile stations may be required to estimate the quality of the radio link (which they do in any way for the purpose of the new call selection) and switch between the two modes depending on the quality of the radio link. In a first mode, the mobile stations may be required to read the PAD channel, while in a second mode the mobile stations are required to process the PCH according to the prior art, that is, they completely decode the PCH. The uniform information and the deviated decision as previously described are recommended. If the PAD channel is implemented in the two bits immediately preceding the PCH segment, an alternative MRLQ process can be used. For example, a channel quality estimate of the synchronization word and / or the two reserved bits can be used with the MRLQ process, instead of a channel quality estimate based on CSFP. Preferably, the MRLQ process does not require reading more data than those that the mobile station is requesting to read for other reasons. In yet another embodiment of the present invention, the PAD channel includes the reserved bits at the end of the segment immediately preceding the PCH segment and the reserved bits in the CSFP field of the PCH segment. A two-stage decoding process can be used with said mode. When the channel conditions are adequate, the mobile station reads the two PAD channel bits immediately preceding the PCH segment. When the channel conditions degrade, the mobile station can switch to read the PAD channel bits in the CSFP field. Therefore, when the channel conditions are adequate and the mobile station is operating in the first mode, the mobile station can prevent the decoding of most of the PCH segment. Switching between the first and second modes can be done depending on any channel quality estimate, such as, an estimate of the quality of the data received during the synchronization word and / or the PAD channel itself. For a two-stage PAD implementation, the range of the first PAD data need not be the same for the second PAD data. For example, due to the lower redundancy (ie the lower reliability), the first stage can transmit only two values: reading and not reading. The second stage may contain additional refinements in its ability to inform mobile stations that data is contained in the PCH for example for Table 1. The system can be capable at any stage of a multiple stage PAD channel independently by the use of mobile station specific messages (addressed messages) or common transmission messages as described above. The TIA IS-136 specification is currently proposed to be amended to support the operation of packaged data. A channel structure (PCCH) of packet control channel and idle mode operation similar to DCCH has been proposed, f 10 using a superstructure frame similar to that shown in Figure 1 1. A link segment structure Descending proposed PCCH is shown in Figure 1 1 D. Like DCCH, the DCCH segments include a superstructure phase encoded with the same code (12, 8) that was used for DCCH CSFP. Without However, there are no reserved bits in this proposed segment format, since the bits corresponding to the three bits reserved in CSFP of the DCCH are used for other purposes. f According to another aspect of the present invention, the channel PAD is provided without requiring the use of DATA (or other) fields of the PCCH. According to this technique, mobile stations can achieve energy savings as when they are inactive in the DCCH using the PAD channel described above. The coded data structure type (CDFT) field in the PCCH of Figure 1 1 D is used to implement a function of type of data structure (DFT) that provides variable coding of the transmitted data. According to the DFT function, the CDFT informs the mobile station about the type of modulation and / or the type of channel coding that is used in the rest of the time segment (ie of the DATA field), with the SYNC field and the data in the code (12, 8) that are modulated and encoded with a predetermined modulation. The packet data feedback (PCF) field may use demodulation and channel coding according to the data in the presented CDFT field or may also have a predetermined modulation / coding. Within the context of the modes of operation of the PCCH contemplated according to IS-136, the function of the CDFT field that will not be exercised very frequently is considered, that is, the type of modulation and the channel modification will be initially set for an arrangement default, and will not have a chance to change later. For example, 8-PSK can be done as the default selection for modulation of the DATA field. Only when the severe weather dispersion is detected (for example, commonly only in choline terrain) will an alternative modulation be used (eg, DQPSK). Therefore, for a particular location, the type of modulation can be set to 8-PSK for all time segments of all users. According to one embodiment of the present invention, in order to introduce a PAD channel on the PCCH, without reducing the DATA field and to maintain similar procedures for the DCCH, the CDFT field is used to transport the PAD channel as long as it is reserved the ability to revert to the original "modulation selection" function when the need arises. In order to provide this capability, the PBCCH (similar to BCCH in the DCCH) can include a descriptor that informs the mobile stations whether the three bits originally proposed for the DFT function should be interpreted or not by the mobile stations as the DFT function or a PAD channel. Upon acquisition and waiting in PCCH ("connection"), a mobile station reads the PBCCH. If the BCCH data in the PBCCH indicates that the DFT function is enabled, the mobile station processes the PCH segments in a "normal" manner, ie it does not interpret the CDFT field containing a PAD channel and always reads its assigned PCH. However, if the PBCCH data indicates that the PAD channel is enabled, the mobile station reads the PAD channel (and responds accordingly), while ignoring the DFT function. When the DFT function is enabled in this way, the selected type of modulation and channel coding of the DATA field can be indicated in the PBCCH. A three-bit PAD channel that can be mapped on either the The DCCH CFSP or the PCCH CDFT can be used, using procedure and formats for the PCCH that are similar to those described for a PAD channel using the DCCH CFSP. If it is desired to use a two-bit PAD channel, this can be mapped for the two reserved bits of a preceding DCCH segment or for similar bits of the PCCH, ie two other reserved bits on the physical layer, there are three options for the design of the PCCH. The first option is to leave a logical PAD channel transported in the PCCH CDFT that has a reduced range, that is, the contents of the three reserved bits within the code (12, 8) can be the same. The second option is to redefine the PBCCH scope based on the PAD channel so that it includes the functions that are assigned to the other two bits reserved for the DCCH. The third option is to redefine the segment format of the PCCH to include two bits for the PAD channel, preferably located near the word synchronization (before or after) as for each DCCH. If the system wishes to activate the DFT function from a deactivated state, the data in the PBCCH will change and the associated change signal will alternate. This change signal can, as explained for the case of DCCH, be part of the scope of the PAD channel and also be placed in the L2 structure as for the DCCH. Therefore, mobile stations that are already in the inactive mode may be that those subsequent data transactions must be executed with the DFT function enabled. Another benefit that can be provided by this embodiment of the present invention is that the mobile station can avoid making the same erroneous interpretations of the actual modulation / coding being used. When the PBCCH signals to the mobile station that the DFT function is disabled, the mobile station can completely bypass the reading of the CDFT field, thus avoiding the loss in data production caused by the wrong decoding of the DFT function. This disabling of the DFT function may not necessarily indicate that the PAD channel, or any other function is enabled. A technique for informing a mobile station from an original reserved set of bits or an individual bit is still reserved for a predetermined value, or has been assigned to a new function described in U.S. Patent No. 5,751. , 731. This technique can be expanded, in accordance with the present invention to allow the different generation of mobile stations to execute different appropriate operations depending on the state of the reserved bits. For example, a first mobile generation station can be informed that it makes use of the set of reserved bits for predetermined values in improving the performance of the channel decoding, for example, the formation corresponding to CSPF can be decoded in accordance with the associated code (12, 8) that can be used as synchronization information and for the equalizer or demodulator. However, if the first mobile generation station is informed that the reserved bits are assigned to a second generation function, for example for a PAD channel, the first mobile generation station can treat the reserved bits as unknown bits and use the alternative synchronization information. A second generation station that supports the new function can use the added functionality. For example, when a control channel (eg BCCH) indicates that a CFSP or CDFT field is used for a function, the second generation station can implement this to represent that the field in question includes a PAD channel and can use the field information in question accordingly. A third generation station can interpret the information received from the control channel indicating that another function is enabled and can therefore process the information in the field in question in this way. Therefore, information about a set of bits provided to mobile stations in u? Control channel (for example in the BCCH) can indicate "reserved", function 1, function 2, function n. The error in the decoding of the PAD channel can introduce decision errors of two types. A first type of error occurs when the decoded PAD data indicates the reading of the associated PCH message that is required when, in fact, the originally transmitted PAD data instructed that reading was not required., resulting, for example, in the decoding of an empty page. A second type of error occurs when the decoding PAD information indicates that there is no required reading of the associated PCH when, in fact, the reading of the associated PCH message is required. The errors of the first type are generally harmless, since the mobile station continues to process a non-relevant PCH and finally (after PCH decoding) arrives at a correct decision that this is a non-relevant PCH (for example, a message does not PCH for example an ARCH message). If such errors are rare (for example, less than 1% error rate), the mobile station can still make significant energy savings from a timely detection capability provided by the PAD channel. The errors of the second type, on the other hand, may be more important. This error implies that the mobile station was paged (this is also possible that the non-empty page is destined for another mobile station), even though it did not read the page and therefore can lose a call. However, since a typical mobile station only receives a few calls per day, the instances in which it will miss a call due to a PAD reading failure may be rare. However, errors of the second type, although they are rare, are of greater interest since they could degrade the level of service received by the user of the mobile station. When using the PAD channel reading technique of the test for a non-relevant PCH, it is generally desirable to reduce data processing as much as possible while minimizing all types of decision errors. However, due to the relative importance of the two types of error, it may be desirable to control the errors of the second type at the expense of errors of the first type. The desired deviation can be achieved through computer simulations or calculations, or from experiments with mobile stations in the field, which reveal the preferred channel decoding method or ideal PAD in order to keep the errors of the second type below a certain level. The decision threshold (read PCH / unread PCH) can be deviated so that most errors committed by the mobile station are of the first type instead of the second type. For example, with the PAD channel coding as defined in Table 8, if any of the three bits in the PAD channel is interpreted as a "1", the mobile station could read the associated PCH message. The decision as to whether or not to read a particular PCH message can be based on "uniform" decoding instead of "permanent decision", that is, the quality (probability of correct received data) of the received PAD channel bits that can be received. be factored when the decision is made whether or not to read PCH. For example, the probability that the PAD data are all zeros ("000") and that they are all ones ("111") can be compared. The logarithmic probability of each bit can, for example, be sied as negative for a bit that is probably sent as zero (0) and sied positive for a bit that has a higher probability to be sent as one (1). The logarithmic probabilities can be appropriately sied and summed to produce a new decision variable (X). The combination of the use of the deviated and uniform decision is also possible, that is, the threshold of the logarithmic probability summed per bit for the reading of the PCH may not be symmetric, that is, it does not need to be centered at zero (for the example of coding defined in table 8 which only has two values). In practice, the decision threshold may have to be continuously adjusted to optimize performance in view of the quality of the current radio channel as reflected in the received si strength (RSS), the si-to-noise ratio (SNR), the structure error regime (FER), the bit error rate (BER) or some other measured or estimated channel quality measurement made by the mobile station. Higher RSS or SNR or lower FER or BER generally implies a higher channel quality, which may allow the mobile station to move the threshold from a more conservative position to a less conservative position. Conversely, lower RSS or SNR or higher FER or BER may imply lower channel quality, which may require the mobile station to move the decision threshold from a less conservative position to a more conservative position. For example, if the mobile station is testing a non-relevant PCH and the decision threshold is set to zero (ie, the decision variable X is compared to zero), the mobile station may instead use a threshold of - d (compare X with -d) if the channel quality is improved and conversely, a threshold of + d (compare X with + d) if the channel quality deteriorates. A wireless station may also be configured to operate in a full decode mode in which it completely decodes all PCH segments as in the prior art, or a refined decoding mode in which it decodes the PCH segments according to the teachings of the present invention. These two modes can be called by the mobile station at different times and under different circumstances. For example, the mobile station can use the full decode mode as a reference to adaptively adjust the decision threshold in the refined decoding mode. This can be implemented by placing the mobile station in an initial training phase in which it calls both decoding modes (perhaps starting with a relatively conservative decision threshold for the refined decoding mode). During this training phase the mobile station compares the decisions made by the refined decoding mode with the actual output as determined from the total decoding mode, and then adjusts the decision threshold in the refined decoding mode to reduce the Minimum errors (for example, errors of the second type as previously described). After this initialization phase, the mobile station will call only the refined decoding mode except at predetermined intervals (or in response to particular events) when it once again adjusts its decision threshold. It should be noted that the decoding of the PAD channel that is being transmitted within another code (for example the code (12, 8)) can take many forms such as a two-step decoding or executed in a single step. If a two-stage decoding is executed, the decoding of the code (12,8) can be permanent or uniform, and one-bit or no-bit errors can be corrected. Many variations are possible. In the case of IS-1 36 when the SFP value is known when entering the mode inactive, the decoding can be executed as a code (7, 3) that has 8 code words. If the PAD encoding as • described in Table 8 is used, where there are only two entries, the code (7, 3) is effectively a code (7, 1) that has two code words. The probability of the first and second word of code are transmitted can be compared in the decision making (uniform information and / or threshold of deviated decisions are applicable). The PAD channel modalities as described above, can be expected to allow the mobile station • 20 avoid the total processing of the majority (for example up to 85-95%) of the PCH segments received during a period of one day. Note that the third type of PAD channel pool (which uses a specific mobile station message or BCCH message) includes the methods used to define the first and second type of groupings (predefined assignment) as a special case. However, the third grouping type allows different methods for different mobile stations and the system to change their group definition strategy over time. In addition, the system can enable and disable functions of the PAD channel during the time, for example the time of day. For example, the system can change from a scenario that has the complete PAD channel as described in table 8 to have the PAD channel as it is in table 1 as well as having the two reserved bits before the SYNC presented taking the function that they are signals of change for BCCH. Figures 17-24 are flow chart illustrations showing exemplary operations for providing PAD channel functionality as described above in a wireless communication system in accordance with aspects of the present invention. It will be understood that the blocks of the flowchart illustrations of Figures 17-24 and the combinations of blocks in the flowchart illustrations can be implemented using electronic circuits included in the wireless stations such as the wireless terminal 400 and the wireless station. 600 base shown in Figures 4 and 6 respectively. It will also be appreciated that the blocks of the flowchart illustrations of Figures 17-24 and the combinations of blocks in the flow chart illustrations can be implemented using components other than those illustrated in Figures 4 and 6, and that, in general, the blocks of the flow chart illustrations of Figures 17-24, and the combinations of blocks in the flowchart illustrations, can be implemented in special purpose hardware such as • discrete analog and / or digital circuits, such as the 5 combinations of integrated circuits or one or more application-specific integrated circuits (ASI Cs), as well as computer program instructions that can be loaded into a computer or other device. programmable data processing to produce a machine so that the instructions running on the computer or other programmable data processing apparatus create means to implement the functions specified in the block or blocks of the flowchart. Computer program instructions may also be loaded onto a computer or other device programmable data processing to cause a series of operating steps to be executed on the computer or other programmable apparatus to produce a computer-implemented process so that the instructions executed in the • computer or other programmable device provide stages for implement the functions specified in the flow chart block (s). Accordingly, the blocks of the flowchart illustrations of Figures 17-24 support electronic circuits and other means for executing the specified functions, as well as combinations of stages to execute the specified functions.

It will be understood that the circuits and other media supported by each block of the flow chart illustrations of Figures 17-24 and combinations of blocks therein, may be implemented by special purpose hardware, software or firmware operating on special processors or of generic purpose data or combinations thereof. Figure 17 illustrates example operations 1700 according to one embodiment of the present invention, which provides PAD functionality on a control channel that carries page messages. A signal representing a page message and an associated PAD are transmitted on at least one DCCH or PCCH segment (block 1710). The transmitted signal received at a wireless station, such as the wireless terminal 400 of Figure 4 (block 1720). The received signal is processed to a sufficient degree to recover the PAD (block 1730). If the recovered PAD meets a predetermined criterion, for example, if the PAD includes information indicating that the receiving wireless station needs to retrieve the associated page message, such as a group value assigned to the wireless station or a change signal indicating a change in supplementary information L2, the wireless station additionally processes the received signal to retrieve the page message (block 1740). Otherwise, the wireless station performs additional processing, thereby allowing the wireless station, for example, to return to idle mode and conserve power (block 1750). Figure 18 illustrates operations 1800 to provide an embedded PAD channel within a page message that is transmitted over a control channel, in particular, within a PCH message transmitted in a DCCH or PCCCH segment. A signal burst representing a page message including a PAD in it, for example in the CSFP field of the page message, is transmitted in a DCCH (or PCCH) segment (block 1810) and is received in a wireless station (block 1820). The received signal burst is processed, for example demodulated and decoded to a sufficient degree to recover the PAD, for example, by demodulating the received signal burst sufficiently to recover the data corresponding to the CFSP field and decode the data to recover the PAD (block 1830). If the recovered PAD meets a predetermined criterion, for example, if the PAD includes the information indicating that the receiving wireless station needs to recover the associated page message, such as a group value assigned to the wireless station or a signal of change indicating a change in the supplementary information L2, the wireless station further processes the received station to retrieve the page message (block 1840). Otherwise, the receiving wireless station proceeds with the additional processing of the received signal burst (block 1850). Figure 19 illustrates operations according to yet another embodiment of the present invention, in which, a PAD functionality is provided outside of the paging channel. A first signal burst including a PAD is transmitted in a first segment, for example, in the reserved bits of a segment preceding a DCCH segment carrying a page message in a PCH (block 1910). A second signal burst including a page message is transmitted in a second segment, for example, in the DCCH segment carrying the page message PCH (block 1920). The first and second signal bursts are received in a wireless signal (block 1930). The second received signal burst is processed sufficiently to recover the synchronization information therein (block 1940). The first received signal burst may then be partially processed using the recovered timing information to recover the PAD (block 1950). If the recovered PAD meets a predetermined criterion, for example, if the PAD includes information indicating that the receiving wireless station needs to retrieve the associated page message, such as a group value assigned to the wireless station or a change signal indicating a change in supplementary information L2 , the wireless station further processes the second received signal burst to retrieve the page message (block 1960). Otherwise, the receiving wireless station proceeds with further processing of the second received signal burst (block 1970).

Figure 20 illustrates operations 2000 according to another embodiment of the present invention, in which the change signals are used to signal the content of the control information in a page message. A signal representing a page message and an associated PAD that includes a signal, such as a signal associated with the previously described GA, PCON, BCN, S-BCN or PFM values (or a signal representing a combination of multiple values of that type), is transmitted over at least one segment DCCH or PCCH (block 2010). The transmitted signal is received at a wireless station such as the wireless station 400 of Figure 4 (block 2020). The received signal is processed to a sufficient extent to recover the change signal (block 2030). If the recovered change signal indicates that a change has occurred then that requires the receiving wireless station to retrieve the associated page message, the wireless station further processes the received signal to retrieve the page message (block 2040) and the wireless station it is then controlled based on the control information in the recovered page message (block 2045). Otherwise, the wireless station proceeds with the additional processing, thereby allowing the wireless station, for example, to return to idle mode and conserve power (block 2050). Figure 21 illustrates operations 2100 according to another embodiment of the present invention, in which an MRLQ functionality is provided by decoding a PAD channel carrier in the CFSP field of the PCH messages and using the resulting decoding metric instead of the normal CRC test performed according to IS-136. An MRLQ counter is initialized, for example, on a standby wireless station on a DCCH (block 2110). The wireless station receives a burst of PCH signal that includes a PAD in its CSFP field (block 2120). The wireless station processes the signal burst to a sufficient degree to recover the CSFP field (block 2130), and decodes the recovered CSFP field to retrieve the PAD and generate an accompanying decoding error estimate (block 2140). If a decoding error is detected, the MRLQ counter is decremented (block 2150). In case no decoding error occurs, the MRLQ estimate is increased, but not more than a predetermined maximum value (block 2160). If the MRLQ counter has not reached zero, the wireless station moves to receive the next PCH burst (block 2120), and repeats the subsequent operations described above. If the MRLQ counter has reached zero, the wireless station can declare a link failure and take additional actions, such as searching for a new DCCH (block 2170). As described above and illustrated by the operations 2200 of the embodiment shown in FIG. 22, this MRLQ function can be modified to compensate for the differences between the coding applied to the CSFP field and the CRC code normally used for MRLQ according to IS-136. Referring to Figure 22, an MRLQ-1 counter and an MRLQ-2 counter of a wireless station are initialized, for example, waiting for a wireless station in a DCCH (block 2205). The wireless station receives a burst of PCH signal including a PAD in a CSFP field (block 2210), and processes the received burst sufficiently to recover the CSFP field (block 2215). The wireless station then decodes the CSFP field to recover the PAD and generates an accompanying error estimate (block 2220). If a decoding error occurs, the MRLQ-2 counter is decremented (block 2215). In case the decoding error does not occur, the counter MRLQ-2 is incremented (up to a maximum value) (block 2230). If the counter MRLQ-2 has already reached zero, the wireless station continues to receive the next PCH signal burst (block 2210) and the operations described above are repeated. If the MRLQ-2 counter has reached zero, the wireless station further processes the received signal burst to recover the page message completely (block 2235), and then conducts a CRC test on the recovered page message (block 2240). If an error is present, the wireless station decreases the MRLQ-1 counter (block 2245). In case no error is detected, the wireless station increments the MRLQ-1 counter (block 2250). If the MRLQ-1 counter has reached zero, the wireless station declares a link failure and proceeds to execute related functions in response, such as the attempt to acquire a new DCCH (block 2255). If the counter MRLQ-1 has exceeded a predetermined value, the wireless station restores the MRLQ-2 counter (block 2260) and returns to the first PAD recovery operations (block 2210 et seq.). Otherwise, that is, if the MRLQ-1 value is greater than zero but higher than the default value that activates the restoration of the MRLQ-2 counter, the wireless station continues to receive PCH bursts, fully retrieves the page messages from them. and modifies the MRLQ-1 counter accordingly (blocks 2265 et seq.) until any link failure is declared or the MRLQ-1 counter reaches a sufficiently high value to guarantee the inversion of the first PAD operation (blocks 2210 et seqJ Figure 23 illustrates operations 2300 according to another aspect of the present invention, in which the interpretation of a retrieved PAD is guided by a coding rule (eg, the rules described with reference to tables 1-8) that is communicated to a wireless station A PAD encoding rule is communicated to a wireless station, for example, over a transmission channel, in a region response message. transmitted to the wireless station, or as part of an OATS procedure. (Block 2310). A page message and the associated PAD are transmitted later (block 2320) and the transmitted PAD recovered in the wireless station (block 2330). The recovered PAD is decoded according to the PAD encoding rule reported previously, for example, according to one of the respective rules in Tables 1-8 (block 2340). The wireless station then determines whether or not the transmitted page message is retrieved based on the decoded PAD (block 2350). Figure 24 illustrates operations 2400 according to another aspect of the present invention, in which a wireless station can operate in a "PAD-enabled" mode in which the wireless station uses recovered PAD values to potentially reduce the number of messages of page decoding, and a "disabled by PAD" mode in which the wireless station retrieves the page messages regardless of the associated PAD values, for example, in a "normal" IS-136 form. A signal representing a page message and an associated PAD are transmitted (block 2410). The signal is received at the wireless station (block 2420). If the wireless station is in the PAD-enabled mode, it retrieves the transmitted PAD and then determines whether or not the transmitted page message is retrieved based on the recovered PAD (block 2430). If the wireless station is in the PAD disabled mode, it retrieves the page message regardless of the PAD (block 2440). It will be understood that recovery "regardless of the PAD" does not prevent normal page message constraints, such as paging structure class limitations and the like.

It will be appreciated that the operations of Figures 17-24 are presented for illustrative purposes, and that the present invention encompasses operations beyond those illustrated in Figures 17-24. For example, the operations of Figure 19 can be modified to eliminate recovery of synchronization information, with blind synchronization techniques used since retrieving the PAD information. Furthermore, although the description of the operations of Figs. 17-24 refers to the control channel structures along the line of these used in systems compatible with IS-136, the present invention can also find application within the system compatible with other standards, such as GSM. In the drawings and specification, typical preferred embodiments of the invention have been described and, although specific terms were used, they are used in a generic and descriptive sense only and not for limitation purposes, and the scope of the invention is set forth in the attached claims.

Claims (53)

1. A communication method in a wireless communications system that is operative to communicate over a physical channel defined as a series of repetition time segments, characterized in that the method comprises: transmitting a page attribute descriptor (PAD) in at least one of a first segment of the physical channel and a second segment of time of the physical channel that happens to the first segment of time, the PAD indicating the content of a page message; transmit the page message in the second time segment; recover the PAD in a wireless station; and determine whether or not the page message is retrieved based on PAD recovered.

A method according to claim 1, characterized in that it comprises one of the following steps: retrieving the page message if the recovered PAD meets a predetermined criterion; or refrain from retrieving the page message if the recovered PAD does not meet the predetermined criteria.

3. A method according to claim 1 characterized in that the step of transmitting a PAD comprises the step of transmitting a signal including the PAD in a time segment assigned to a paging channel; wherein the stage of recovery of the PAD comprises the steps of: receiving the signal at the wireless station; and demodulating the received signal to a sufficient degree to recover the PAD.

4. A method according to claim 3, further comprising the step of proceeding with further demodulation of the received signal if the recovered PAD meets a predetermined criterion.

A method according to claim 3: wherein the step of transmitting a signal comprises the step of transmitting a signal burst representing the page message and the PAD in a digital control channel time segment (DCCH) assigned to a paging channel (PCH); wherein the step of recovering the PAD comprises the steps of: receiving the transmitted signal burst at the wireless station; and process the received signal burst to recover the PAD.

6. A method according to claim 5, characterized in that the step of transmitting a signal burst comprises the step of transmitting a signal burst representing a physical layer message including a coded superstructure phase field (CSFP) which includes the PAD.

7. A method according to claim 6, further comprising the steps of: recovering a CSFP field from the received signal burst; decode the CSFP field; generate an error estimate for the decoded CSFP field as an estimate of the transmitted CFSP field; and determine the link quality based on the error estimate generated.

A method according to claim 3, characterized in that the step of transmitting a signal comprises the step of transmitting a signal burst representing the page message and the PAD in a packet data control channel time slot. (PCCH) assigned to a paging channel (PCH).

9. A method according to claim 8, characterized in that the step of transmitting a signal burst comprises the step of transmitting a signal burst representing a physical layer message including a coded data structure type field (CDFT) that includes the pad.

A method according to claim 1: wherein the step of transmitting a PAD is preceded by the step of informing the wireless station if a PAD channel is enabled; and wherein the step of recovering the PAD comprises the step of recovering the PAD that responds to the wireless station that is informed that the PAD channel is enabled.

11. A method according to claim 1; wherein the step of transmitting a PAD comprises the step of transmitting a first signal representing the PAD in a time segment preceding a time segment assigned to a paging channel; and wherein the step of transmitting a page message comprises the step of transmitting a second signal representing the page message in the time segment assigned to the paging channel; wherein the reception stage comprises the step of receiving the first and second signals at the wireless station; and wherein the step of recovering the PAD comprises the step of recovering the PAD from the first received signal.

12. A method according to claim 11, further comprising the step of proceeding with the processing of the second signal to retrieve the page message if the recovered PAD meets a predetermined criterion.

13. A method according to claim 12: wherein the step of transmitting a first signal comprises the step of transmitting a first signal burst representing the PAD in a time segment preceding a time segment DCCH assigned to a paging channel (PCH); and wherein the step of transmitting a second signal comprises the step of transmitting a second signal burst representing the page message in time segment DCCH assigned to the PCH.

A method according to claim 13: wherein the step of transmitting a first signal comprises the step of transmitting a first signal burst representing a physical layer message including the PAD at an extreme portion thereof; and wherein the step of recovering the PAD comprises the steps of: receiving the first signal burst transmitted at the wireless station; and demodulating the first received signal burst to a sufficient degree to recover the PAD without demodulating the entire first signal burst.

15. A method according to claim 13, wherein the step of transmitting a second signal burst comprises the step of transmitting a second signal burst that includes a synchronization field in the initial portion thereof; wherein the step of recovering the PAD comprises the steps of: receiving the first and second signal bursts at the wireless station: demodulating the second signal burst to a sufficient degree to recover the synchronization field without demodulating the entire second signal burst; and processing the first received signal burst based on the synchronization information in the recovered synchronization field to recover the PAD.

16. A method according to claim 1: wherein the step of transmitting a PAD comprises the step of transmitting one of a plurality of group values, a respective one of the group values associated with a respective group of wireless stations; wherein the step of recovering the PAD comprises the step of recovering a group value in the wireless station; and wherein the determining step comprises the step of choosing the recovery of the page message if the recovered group value is associated with a group of wireless stations of which the wireless station is a member.

17. A method according to claim 1: wherein the step of transmitting a PAD comprises the step of transmitting a PAD including a signal indicating the status of the control information included in the page message; wherein the step of recovering the PAD comprises the step of recovering the signal at the wireless station; and wherein the step of recovering the signal is followed by the step of controlling the wireless station based on the recovered signal.

18. A method according to claim 1, wherein the step of transmitting a PAD comprises the step of transmitting a PAD encoded according to a first determined code; wherein the step of recovering the PAD comprises the steps of: receiving a signal at the wireless station; and processing the received signal to generate the data corresponding to the encoded PAD; and wherein the method further comprises the steps of: decoding the data generated in accordance with the first predetermined code to generate a transmitted estimate and PAD; generate an error estimate for the generated estimate of transmitted PAD; and determine the link quality from the error estimate generated.

19. A method according to claim 18: wherein the step of transmitting the page message comprises the step of transmitting the encoded page message according to a second predetermined code; wherein the step of determining link quality comprises the step of determining a first measure of link quality based on the generated error estimate for the estimate of the transmitted PAD; and wherein the method further comprises the following steps, performed if the first link quality measurement meets a predetermined criterion: retrieving the data corresponding to the page message in the wireless station; decoding the retrieved data corresponding to the page message according to the second predetermined code to generate an estimate of the page message; generate an error estimate for the page message estimate; and determining a second measure of link quality based on the error estimate generated for the page message estimate.

20. A method according to claim 1, characterized in that the determination step comprises the step of diverting a decision whether the page message is retrieved or not to one of the page message retrieval or the recovery to recover. the page message. twenty-one .

A method according to claim 1, further comprising one of the following steps: recovering the page message transmitted on the wireless station if the PAD meets a predetermined criterion and the wireless station is in a first mode; or retrieve the transmitted page message regardless of the recovered PAD if the wireless station is in a second mode.

22. A method of operation and a wireless station, characterized in that the method comprises: retrieving a paging attribute descriptor transmitted from at least one of a first time segment of a physical channel defined as a series of repetition time segments and a second time segment of the physical channel that succeeds the first time segment, the PAD indicating the content of a page message transmitted in the second time segment; and determine whether or not the page message is retrieved based on PAD recovered.

23. A method according to claim 22, further comprising one of the following steps: retrieving the page message if the recovered PAD meets a predetermined criterion; or renounce the recovery of the page message if the recovered PAD does not meet the predetermined criteria.

24. A method according to claim 22, characterized in that the step of recovering a transmitted PAD comprises the steps of: receiving a signal at the wireless station; and demodulating the received signal to a sufficient degree to recover the PAD.

25. A method according to claim 24, further comprising the step of proceeding with further demodulation of the received signal if the recovered PAD meets a predetermined criterion.

26. A method according to claim 24, characterized in that the step of recovering a transmitted PAD comprises the steps of: receiving a signal burst representing the page message and the PAD in the digital control channel time segment ( DCCH) assigned to a paging channel (PCH); and process the received signal burst to recover the PAD.

A method according to claim 26, characterized in that the step of receiving a signal burst comprises the step of receiving a signal burst representing a physical layer message including a coded superstructure phase field (CSFP) which includes the PAD.

28. A method according to claim 27, further comprising the steps of: recovering a CSFP field from the received signal burst; decode the CSFP field; generate an error estimate of the decoded CSFP field as an estimate of the transmitted CFSP field; and determine the link quality based on the error estimate generated.

29. A method according to claim 24, characterized in that the step of receiving a signal comprises the step of receiving a signal burst representing the page message and the PAD in a packet data control channel (PCCH) time slot assigned to a paging channel. (PCH).

30. A method according to claim 29, characterized in that the step of receiving a signal burst comprises the step of receiving the signal burst representing a physical layer message including a coded data structure type field. (CDFT) that includes the PAD.

31. A method according to claim 22: wherein the step of recovering a PAD is preceded by the step of determining that a PAD channel is enabled; and flj) wherein the step of recovering a transmitted PAD comprises the step of recovering the PAD that responds to the determination that that PAD channel is enabled.

32. A method according to claim 22, characterized in that the second time segment comprises a time segment DCCH assigned to a paging channel (PCH).

33. A method according to claim 22, wherein the step of recovering a transmitted PAD comprises the steps of: receiving a first signal burst representing a physical layer message including the PAD at an extreme portion thereof; and demodulating the first received signal burst to a sufficient degree to recover the PAD without demodulating the entire first signal burst.

34. A method according to claim 33, wherein the step of recovering a transmitted PAD comprises the steps of: receiving a first signal burst representing a physical layer message including the PAD at an extreme portion thereof; receiving a second signal burst that includes a synchronization field in an initial portion thereof; demodulating the second received signal burst to a sufficient degree to recover the synchronization field and demodulate the entire second signal burst; and processing the first received signal burst based on the synchronization information in the recovered synchronization field to recover the PAD.

35. A method according to claim 22: wherein the step of recovering a transmitted PAD comprises the step of recovering a group value; and wherein the determining step comprises the step of choosing to retrieve the page message if the recovered group value is associated with a group of wireless stations of which the wireless station is a member.

36. A method according to claim 22: wherein the step of recovering a transmitted PAD comprises the step of recovering the signal indicating the status of the control information included in the page message; and wherein the determination step comprises the step of determining whether the page message is retrieved based on the recovered signal.

37. A method according to claim 22: wherein the step of recovering a transmitted PAD comprises the steps of: receiving a signal at the wireless station; and processing the received signal to generate the data corresponding to the PAD; and wherein the method further comprises the steps of: decoding the generated data according to a first predetermined code to generate an estimate of the transmitted PAD; generate an error estimate for the generated estimate of the transmitted PA D; and determine the link quality from the error estimate generated.

38. A method according to claim 37: wherein the step of determining the link quality comprises the step of determining a first measure of the link quality based on the generated error estimate for the estimate of the transmitted PAD; and wherein the method further comprises the following steps, performed if the first link quality measure meets a predetermined criterion: retrieving the data corresponding to the page message in the wireless station; decoding the retrieved data corresponding to the page message according to a second predetermined code to generate an estimate of the page message; generate an error estimate for the page message estimate; and determining a second measure of link quality based on the generated error estimate for the page message estimate.

39. A method according to claim 22, characterized in that the determination step comprises the step of diverting a decision to retrieve the page message to one of the page message retrieval or the page message retrieval of the message. .

40. A method according to claim 39, characterized in that the deflection step comprises the step of deflecting the decision whether the page message is retrieved based on at least one of the channel quality and the precision in the recovery of a previously transmitted PAD.

41. A method according to claim 22, further comprising one of the following steps: recovering the page message transmitted on the wireless station if the recovered PAD meets a predetermined criterion and the wireless station is in a first mode; or retrieve the transmitted page message regardless of the recovered PAD if the wireless station is in a second mode.

42. A wireless station, characterized in that the wireless station comprises: means for retrieving a PAD transmitted page attribute descriptor from at least one of a first time segment of a physical channel defined as a series of repetition time segments and a second segment of the physical channel that succeeds the first time segment, the PAD indicating the content of a page message transmitted in the second time segment; and means for determining if the page message is recovered based on the recovered PAD.

43. A wireless station according to claim 42, further comprising means for retrieving the page message if the recovered PAD meets a predetermined criterion and for forgoing the recovery of the page message if the retrieved PAD does not meet the predetermined criterion. .

44. A wireless station according to claim 42, characterized in that the means for recovering a transmitted PAD comprises: means for receiving a signal burst representing the page message and the PAD in a digital control channel time segment. (DCCH) assigned to a paging channel (PCH); and means for processing the received signal burst to recover the PAD.

45. A wireless station according to claim 44, characterized in that the means for receiving a signal burst comprises means for receiving a signal burst representing a physical layer message including a coded superstructure phase field (CSFP) that includes the PAD.

46. A wireless station according to claim 45, further comprising: means for recovering a CSFP field from the received signal burst; means to decode the CSFP field; means for generating an error estimate for the decoded CSFP field as an estimate of the transmitted CFSP field; and means to determine link quality based on the generated error estimate.

47. A wireless station according to claim 42, characterized in that the means for recovering a transmitted PAD comprises means for receiving a signal burst representing the page message and the PAD in a packet data control channel (PCCH) time slot assigned to a paging channel ( PCH).

48. A wireless station according to claim 47, characterized in that the means for receiving a signal burst comprises means for receiving a signal burst representing a physical layer message including a coded data structure type field (CDFT). ) which includes the PAD.

49. A wireless station according to claim 42, characterized in that the means for recovering a transmitted PAD comprises means for recovering the PAD from the first time segment.

50. A wireless communication system, characterized in that the wireless communication system comprises: means for transmitting a paging attribute descriptor (PAD) in at least one of a first time segment of the physical channel comprising a series of segment of repetition time and a second time segment of the physical channel that happens to the first time segment, the PAD indicating the content of a page message; and means for transmitting the page message in the second time segment.

51. A system according to claim 50, characterized in that the means for transmitting a PAD comprise the step of transmitting a signal including the PAD in a time segment assigned to a paging channel.

52. A system according to claim 50, further comprising means for informing a wireless station if a PAD channel is enabled.

53. A system according to claim 50: wherein the means for transmitting a PAD comprise means for transmitting a first signal representing the PAD in a time segment preceding a time segment allocated for a paging channel; and wherein the means for transmitting a page message comprises means for transmitting a second signal representing the page message in the time segment assigned to the paging channel.