MXPA99011043A - A method of and apparatus for paging a wireless terminal in a wireless telecommunications system - Google Patents

A method of and apparatus for paging a wireless terminal in a wireless telecommunications system

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Publication number
MXPA99011043A
MXPA99011043A MXPA/A/1999/011043A MX9911043A MXPA99011043A MX PA99011043 A MXPA99011043 A MX PA99011043A MX 9911043 A MX9911043 A MX 9911043A MX PA99011043 A MXPA99011043 A MX PA99011043A
Authority
MX
Mexico
Prior art keywords
radiolocation
rapid
message
complete
channel
Prior art date
Application number
MXPA/A/1999/011043A
Other languages
Spanish (es)
Inventor
S Gilhousen Klein
K Butler Brian
Original Assignee
Qualcomm Incorporated
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to US08865650 priority Critical
Priority to US08890355 priority
Application filed by Qualcomm Incorporated filed Critical Qualcomm Incorporated
Publication of MXPA99011043A publication Critical patent/MXPA99011043A/en

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Abstract

A method of and apparatus for paging a wireless terminal in a wireless telecommunications system reduce standby mode power consumption. A minimally encoded quick paging channel is established over which short, quick page messages (30) are transmitted during one of a set of quick paging slots. The quick page message indicates that a communications request has been received, and that the receiving communication terminals should process a highly encoded full paging channel over which more detailed, full page messages (32) are transmitted during the next full paging slot. A terminal monitors full paging channel only after a quick page message has been received on the quick paging channel.

Description

- .. JJ A METHOD AND AN APPARATUS FOR SENDING SIGNALS OF LOCALIZATION TO A WIRELESS TERMINAL, IN A WIRELESS TELECOMMUNICATION SYSTEM b -. ANTECEDEHTES DE LA IKVEWCIQM I. FIELD OF THE INVENTION The present invention relates to a method and apparatus for the radiolocation of a wireless terminal, in a wireless telecommunications system. More specifically, the present invention relates to a new and improved method and apparatus for radiolocation of a cellular telephone or other wireless communication device. Radiolocation can be carried out using a rapid radiolocation channel and a complete radiolocation channel.
II. Description of the Related Art 0 The IS-95 cellular telephone standard (and its derivatives such as IS-95A and ANSÍ J-STD-008 collectively referred to herein as IS-95) uses advanced signal processing techniques for provide an efficient and high quality 5 cell phone service. For example, a cell phone system in accordance with IS-95 uses voice coding, error detection, early error correction (FEC), interleaving and P1729 / 99MX extended spectrum modulation in order to make more efficient use of the available RF bandwidth, and to provide stronger connections. In general, the benefits provided by IS-95 include a longer talk time, increased capacity and fewer dropped calls when compared to other types of cellular telephone systems. To conduct communications in an orderly fashion, the IS-95 provides a set of highly coded channels on which data with different functions are transmitted. This highly coded data includes a radiolocation channel over which are transmitted radiolocation messages that notify cell phones or other types of wireless terminals that an incoming request to communicate is pending. In accordance with IS-95, radiolocation messages are transmitted at data rates, low to medium (4800 to 9600 bps) during time intervals that are pre-assigned to cell phone groups. Table I provides the data included in a general radiolocation message as an example of the typical radiolocation message generated substantially in accordance with the IS-95A standard.
P1729 / 99MX TABLE I And zero or more occurrences of the following radiolocation record: Table I is provided to simply illustrate the length of a typical radiolocation message, so that a detailed description of the function of each field is not included herein. This detailed description can be obtained, however, by referring to the standard P1729 / 99MX IS-95A, well known, publicly available (in particular the IS-95A standard). The radiolocation messages also start with an eight-bit message length field (MSG-LEN), which indicates the length of the message, and end with a 30-bit cyclic redundancy check (CRC) field (not shown). To monitor the radiolocation messages, a cell phone periodically monitors the radiolocation channel during the assigned radiolocation interval. In particular, the cellular telephone periodically activates the complex set of RF circuits and digital signal processing as long as it is necessary to successfully process the radiolocation message. Since the typical radiolocation message is relatively long and is transmitted via a highly coded low-to-medium rate channel, the associated processing during each radiolocation interval requires significant resources of the amount of time and signal processing, and therefore , it requires a significant amount of energy to finish. This reduces the amount of time an IS-95 cell phone can remain in standby mode using a battery of a certain capacity, and therefore, is highly undesirable.
P1729 / 99MX SUMMARY OF THE INVENTION In one aspect, the invention provides a method for radiolocating the wireless terminal in a wireless telecommunications system comprising: transmitting a rapid radiolocation message via a less encoded channel; and generate a complete radiolocation message via a more coded channel. In another aspect, the invention provides a method for radiolocating a wireless terminal from a set of wireless terminals comprising: a) transmitting a rapid radiolocation message addressed to a subset of the set of wireless terminals including the wireless terminal; and b) generating a complete radiolocation message identifying the wireless terminal. The invention also provides a method for radiolocating a wireless terminal comprising: a) generating a rapid radiolocation message; and b) generating a complete radiolocation message, wherein the rapid radiolocation message contains substantially less data than the complete radiolocation message. The invention further provides a method for receiving a radiolocation message comprising the steps of: a) monitoring a fast paging channel for a message of P1729 / 99MX rapid radiolocation; and b) monitor a complete radiolocation channel when a rapid radiolocation message is received. The invention further provides an apparatus for radiolocating a wireless terminal in a wireless telecommunications system, the apparatus comprising: means for transmitting a rapid radiolocation message via a less encrypted channel; and a means for generating a complete radiolocation message and a more coded channel. The present invention is incorporated into a new and improved system method for radiolocating a cell phone or other wireless terminal that reduces the power consumption in the standby mode. Two radiolocation channels can be used. In accordance with one embodiment of the invention, a minimally encoded rapid radiolocation channel is established on which short, rapid radiolocation messages are transmitted for one of a set of rapid radiolocation intervals. A rapid radiolocation message indicates that a request to communicate has been received and that the receiving communication terminals must process a complete, highly coded, radiolocation channel transmitted during the next complete radiolocation interval for a message of P1729 / 99MX complete, more detailed radiolocation. A communications terminal monitors a complete radiolocation channel after a rapid radiolocation message has been received in the fast paging channel. To radiolocate the communications terminal, a base station controller first generates a rapid paging message during a rapid paging interval assigned to a set of communications terminals that includes the particular communications terminals that are radiolocated. This is followed by a complete radiolocation message that identifies the particular communications terminal. The communications terminal periodically monitors the rapid radiolocation interval and upon detecting rapid radiolocation, activates the set of decoding circuits to process the complete radiolocation channel. When processing the complete radiolocation channel, the communication terminal determines whether the complete radiolocation message is directed to it, or if it does not, it deactivates the decoding circuitry and returns to the processing of the fast radiolocation channel.
P1729 / 99MX BRIEF DESCRIPTION OF THE DRAWINGS The above and additional features, objects and advantages of the present invention will become more evident from the detailed description of the embodiments of the invention set forth later when taken together with the drawings in which like reference characters are identified correspondingly throughout the length and in which: Figure 1 is a block diagram of a cell phone system. Figure 2 is a synchronization diagram illustrating the synchronization intervals in a rapid radiolocation channel and a complete radiolocation channel; Figure 3 is a flow chart illustrating the steps performed during radiolocation of a wireless terminal; Figure 4 is a block diagram illustrating the coding performed in the complete radiolocation channel and the fast radiolocation channel; Figure 5 is a flow chart illustrating the steps performed by a wireless terminal during the standby mode; and Figure 6 is a block diagram of a receiver configured in accordance with an embodiment of the invention.
P1729 / 99MX DETAILED DESCRIPTION OF THE PREFERRED MODALITIES A method and system for radiolocating a cellular telephone or other wireless terminal that reduces the power consumption in the standby mode is described. Two radiolocation channels can be used. In the following description, one embodiment of the invention is set forth in the context of a cellular telephone system operating substantially in accordance with the IS-95 standard. While the invention is particularly suitable for operation in this field, many other digital communication systems can benefit from the use of the present invention, including wireless communication systems, based on TDMA, the satellite-based communication system, and the cable line systems over which the coded signaling is transmitted. Figure 1 is a block diagram of a highly simplified cellular telephone system configured for use with the use of the present invention. The wireless terminals 10 (typically cell phones) are located between the base stations 12. The wireless stations 10a and 10b are in the active mode, and therefore, are interconnected with one or more base stations 12 using radio frequency (RF) signals modulated according to the CDMA signal processing techniques of the IS-95 standard. A system and method are described P1729 / 99MX for processing RF signals substantially in accordance with the use of the IS-95 standard in U.S. Patent No. 5,103,459 entitled "System and Method for Generating Signal Waveforms in a CDMA Cellular Telephone System", assigned to this invention and incorporated herein by reference ('459 patent). The other wireless terminals 10 are in standby mode, and therefore, monitoring the radiolocation messages indicating a request to communicate. In the preferred embodiment of the invention, each base station generates forward link signals comprising a set of forward link channels. The channels are established by a set of Walsh codes of 64 orthogonal platelets (or bits) each of which is used to modulate the data associated with a particular channel. The channels are categorized by function and include a pilot channel on which a phase shifting pattern is transmitted repetitively, a synchronization channel on which the synchronization data is transmitted and includes the absolute time of the system and the phase shifting. phase of the associated pilot channel, and traffic channels on which the data directed to the terminals is transmitted. The traffic channels are normally assigned to transmit data to a particular terminal 10 during the duration of the interconnection P1729 / 99MX with that particular base station. Additionally, according to one embodiment of the invention, one or more of the Walsh codes are designated as fast radiolocation channels, and one or more of the Walsh channels as the complete radiolocation channels. The designation and operation of the complete radiolocation channels is preferably carried out in accordance with the radiolocation channel specified by the IS-95 standard. Some methods and apparatus for performing radiolocation substantially in accordance with the IS-95 standard are described in U.S. Patent Nos. 5,392,287 ('287 patent) entitled "APPARATUS AND METHOD FOR REDUCING POWER CONSUMPTION IN A MOBILE COMMUNICATIONS RECEIVER" AND No. 5,509,015, ('015 patent) entitled "METHOD AND APPARATUS FOR SCHEDULING COMMUNICATIONS BETWEEN TRANSCEIVERS", both assigned to the assignee and incorporated herein by reference. As described in the '287 and' 015 patents, and as specified by the IS-95 standard, the complete radiolocation channel is time divided into "time slots". In turn, the intervals are assigned to groups of terminals, where the assignment is made based on the ID of the International Mobile Subscriber (IMSI) that is unique to each wireless terminal 10, or other information P1729 / 99MX terminal identification such as one or more mobile identification numbers (MIN). In alternative embodiments of the invention, other identification information may also be used that includes the electronic serial number (ESN) of the wireless terminal or the temporary mobile subscriber ID (TMSI). Others will recognize additional values that can be used. The various possible types of identification information that may be used will be referred to hereinafter collectively as the MOBILE_ID. Rapid radiolocation channels are also divided into time intervals. Figure 2 is a timing diagram illustrating the time intervals of a complete radiolocation channel and a fast radiolocation channel when configured in accordance with one embodiment of the invention. The rapid radiolocation channel is divided into rapid radiolocation intervals 30 and the complete radiolocation channel is divided into complete radiolocation intervals 32 which are preferably longer in duration than the rapid radiolocation intervals. The sets, or groups, of rapid radiolocation intervals 30 are assigned to individual, complete radiolocation intervals 32 as illustrated by the diagonal arrows although the use of a P1729 / 99MX one-to-one correspondence of the rapid radiolocation intervals and the complete radiolocation intervals, or other ratios, is consistent with the use of the invention. The assignment of the rapid radiolocation intervals 30 to a particular set of wireless terminals is preferably carried out via the application of a key function to the MOBILE_ID of the wireless terminal 10. To radiolocate a particular wireless terminal 10, a radiolocation message is transmitted. Fast during the rapid radiolocation interval and a complete radiolocation message is transmitted during the full radiolocation interval assigned to that wireless terminal. The rapid radiolocation interval and the complete radiolocation intervals occur in a periodically repeating manner, which ensures that a range associated with the particular terminal occurs after some limited period of time. As illustrated in Figure 2, the complete radiolocation slots 32 have a delay 34 after the associated fast paging slots 30 allow the wireless terminal to process the fast paging message and activate the set of decoding circuits, additional before the next complete radiolocation interval.
P1729 / 99 X Figure 3 is a block diagram of the steps performed by BSC 14 during the radiolocation process. The radiolocation process begins in step 36 and in step 38 it is determined whether a request to communicate has been received. If not, step 38 is performed again. If a request has been received to communicate, the complete paging interval and the rapid paging interval associated with the wireless terminal to which the communication request is directed is calculated in step 40. based on the MOBILE_ID or other identification information of that wireless terminal 10. In one embodiment of the invention, the rapid paging interval is calculated using a first key function, and the complete paging interval is calculated using a second function. of keys where the second key function is different from the first key function. Additionally, the complete radiolocation intervals are in the order of 80 ms, while the rapid radiolocation intervals are in the order of 5 ms. The wireless terminal 10 may have to process all or part of the complete radiolocation channel depending on the content of the radiolocation message that is received in accordance with IS-95. The BSC 14 preferably performs the necessary procedure using one P1729 / 99MX or more microprocessors running the memory program stored in memory (not shown). In an exemplary embodiment of the invention, the complete radiolocation range is determined in accordance with the '287 and' 015 patents, referred to above, and the rapid paging interval is determined by the application of another key function to the MOBILE_ID , although the use of other methods for assigning radiolocation intervals to wireless terminals is consistent with the use of the present invention. In particular, the complete radiolocation interval corresponds to the time t of the system, provided in 20 ms frames, where the following equation is true. (floor (t / 4) -PGSLOT) mod (16 * T) = 0 (1) where T is a length of the interval cycle in units of 1.28 seconds given by T = 2X, where i is the index of the interval cycle (SCI). PGSLOT is determined using the following key equation: PGSLOT = floor (Nx ((40505x (L? H? DECOR)) mod2? 16) / 2? 16), (2. where L is the least significant 16 bits of a HASH_? and 32 bits and H is the 16 most significant bits of the HASH_KEY, and N is 2048. The P1729 / 99MX HASH_ EY is preferably the MOBILE_ID or some derivative thereof and the IMSI. The function floor (x) returns the largest integer less than or equal to x. For example, the result of floor (2.99), floor (2.01) and floor (2.00) is 2 and the floor result (-2.5) is -3. DECORR decorrelation value is calculated as follows: DECORR = 6 X HASH_KEY [0..11] (3) Where HASH_KEY [0..11] is the eleven least significant bits of the HASH_KEY value. The function of keys for determining the rapid radiolocation interval in a preferred embodiment of the invention is calculated in a manner similar to the complete radiolocation range, except that the rapid radiolocation range occurs between 40 to 120 ms before the full radiolocation interval. , and the set of wireless terminals assigned to a rapid paging range changes over time to ensure that each wireless terminal 10 is associated with a different set of other wireless terminals 10 during each rapid paging interval. By varying the set of terminals 10 with which each wireless terminal 10 is associated during each radiolocation interval, assistance is given in the P1729 / 99MX ensures that fewer active wireless terminals become permanently associated with a more active wireless terminal 10, and therefore have to unnecessarily monitor a greater number of complete radiolocation messages that do not address it. In an exemplary embodiment of the invention, the rapid radiolocation interval for a wireless terminal 10 is presented in the space of a 80 ms fast paging period starting at 120 ms before the beginning of the full paging interval as calculated by The following equation: [floor ((t-6/4) - PGSLOT) mod (16 * T) = 0 (4) where PGSLOT is the same as that used for the complete radiolocation interval. The duration of the rapid radiolocation period is preferably 80 ms. The rapid radiolocation period is divided into the rapid radiolocation intervals during which the rapid radiolocation messages that are described in greater detail below are transmitted. Preferably, the rapid radiolocation intervals and the associated messages of the complete radiolocation are of a single bit of duration. Therefore, the number of P1729 / 99MX Rapid Radiolocation Intervals by Rapid Radialization Period is a function of the fast radiolocation data rate. As should be evident, equation (4) is the same as equation (1) except that the system time is mismatched by six frames, which causes the beginning of the rapid radiolocation period to start 120 ms before the full radiolocation interval. Providing a misalignment of 120 ms, it is ensured that there is at least 40 ms of time (given the rapid radiolocation period of 80 ms) between any particular rapid paging interval, and the complete radiolocation interval that gives the wireless terminal sufficient time to prepare and process the full radiolocation message after receiving a quick radiolocation message. Within the 80 ms period of full radiolocation, the rapid radiolocation interval (which has a bit duration) assigned to a particular wireless terminal 10 is determined using the following equation: QUICK_PGSLOOT = 1 + floor (Nx ((40505x (L? HFDECORR)) mod2? 16) / 2? 16), (5) with the value N is set to the data rate of the fast paging channel (QPAGE_RATE) in the P1729 / 99MX number of bits per 80 ms interval. For example, if the data rate of the fast paging channel is 9600 bits / second, the value QPAGE_RATE is equal to 768 bits / four. Additionally, the decorrelation value is adjusted as follows: DECORR = floor ((t-6) / 64) mod2? 16. (6) In this way, equation (5) returns to a value of 1 and 768 that corresponds to the fast radiolocation interval (or bit location) within a fast 80 ms paging period that starts 120 ms before the full paging interval correspondent. The wireless terminal monitors the rapid paging channel during this rapid paging interval and if a rapid paging message is received, the wireless terminal will then monitor the entire paging channel for a complete paging message. As should be evident from equation (6), the DECORR de-correlation value for the fast radiolocation channel is calculated as a function of the system time, and therefore, the resulting value QUICK_PGSLOT for a given set of wireless terminals 10 will differ according P1729 / 99MX advance the time. This causes the set of wireless terminals associated with a particular range of full radiolocation to have different ranges of fast paging over time (they can still be paired during the same rapid paging period), which will help to ensure that a wireless terminal 10 less active does not join a more active wireless terminal 10 that will cause it to monitor the entire radiolocation channel with unnecessary frequency, and therefore, unnecessary power consumption. If the M0BILE_ID is not contained directly within the request to communicate, it can be obtained via a database search using any different identification information contained in the request such as the telephone number or the mobile identification number (MIN) of the wireless terminal 10. Once the rapid paging interval and the complete paging interval are determined, the BSC 14 transmits a rapid paging message in step 42 in a fast paging channel, and the complete paging message in the wireless paging channel. step 44 in a complete radiolocation channel, via one or more base stations 12. The base stations 12 encode and modulate the radiolocation channels P1729 / 99MX as described in greater detail below, and the transmission of the two radiolocation messages occurs during the corresponding fast paging interval and the complete paging interval. After transmission of the fast paging message and the complete paging message, the BSC 14 polls a response in step 46 indicating that radiolocation has been received. If a response was received the communication begins in step 50. If no response was received after a period of time, a second rapid paging message is transmitted in step 52, and a second complete paging message is transmitted in step 54. In step 56 the BSC 14 polls for a response from the wireless terminal 10 and determines in step 58 whether a response was received. If a response was received, the communication begins in step 50. If it is determined in step 58 that no response was received, the radiolocation fails in step 60. In an alternative embodiment of the invention, two or more messages are generated from rapid radiolocation and two or more complete radiolocation messages, corresponding, for each radiolocation. The second rapid paging message and the complete radiolocation message increase theP1729 / 99MX the probability that radiolocation will be received, without the introduction of the delay necessary to determine whether a recognition message has been received from the wireless terminal 10. In the preferred embodiment of the invention, the rapid radiolocation message is comprised of a bit of INCOMMING_PAGE. A bit of INCOMMING_PAGE in a first state (such as a high logic level) indicates that a communication request has been received for one of the wireless terminals 10 associated with that rapid paging interval, and therefore these wireless terminals must process the full radiolocation channel during the next designated complete radiolocation interval. A bit of INCOMMING_PAGE in a second state (such as low logic level) indicates that a communication request has not been received for these wireless terminals 10, and therefore the entire radiolocation channel should not be processed during the next radiolocation interval. complete Therefore, the rapid radiolocation message is encoded more highly than the complete radiolocation message, since the radiolocation is represented by an individual bit instead of a substantially larger number of bits, and therefore can be processed with few resources . This coding of "messages" does not P1729 / 99MX should be confused with the coding of the "channel" described below, where a greater amount of coding requires more data processing resources, and therefore is less desirable in terms of power consumption. In the preferred embodiment of the invention, the complete radiolocation message contains information specified in the IS-95 standard for a normal radiolocation message that allows each wireless terminal 10 to determine whether the radiolocation is directed to it. An example of a radiolocation generated in accordance with the IS-95 standard is given in Table I listed above. As illustrated by Table I, the complete radiolocation message contains significantly more information than the rapid radiolocation message, which is preferably comprised of an individual bit. Therefore, the rapid radiolocation message can be processed more easily by each wireless terminal 10 and with less power, than the complete radiolocation message. In alternative embodiments of the invention, multi-bit rapid radiolocation messages are used. These multi-bit rapid paging messages are used to encode and carry additional information beyond merely indicating that the wireless terminal 10 must P1729 / 99MX monitor the complete radiolocation channel during the next assigned, complete radiolocation interval 32. For example, the multi-bit rapid radiolocation message can be used to more particularly indicate which wireless terminal 10 is radiolocating from the wireless terminal sub-set assigned to the corresponding rapid paging interval. The multi-bit rapid paging message can also be used to indicate which full paging channel should be monitored for a longer duration, so that changes to the system parameters can be broadcast to all wireless terminals 10. Those experts In the art they will recognize several useful types of information can be transmitted using a multi-bit rapid radiolocation message. Also, in another relative embodiment of the invention, the reduced coding of the early error correction in the rapid radiolocation message is performed. In addition to transmitting less information in a rapid radiolocation message than in a complete radiolocation message, the preferred embodiment of the invention incorporates a minimum coding scheme for the fast radiolocation channel when compared to the complete radiolocation channel. Figure 4 provides an illustration of P1729 / 99MX the coding schemes used for the complete radiolocation channel and the rapid radiolocation channel according to the embodiment of the invention. As shown in Figure 4, the data transmitted via the complete radiolocation channel is coded convolutionally by the convolutional encoder 60 and the resulting code symbols repeated by the symbol repeater 61 in order to generate symbols at a predetermined rate. The repeated code symbols are then interleaved in blocks by the block interleaver 62. The block interleaver data is retransmitted via EXCLUSIVE-OR (XOR) with a decimated long code generated by the long code generator 64 and the decimator 66. The long code is a binary code generated pre-determined as a function of a searched number, and is known for all wireless terminals 10. The retransmitted data is modulated with a Walsh channel code designated for a complete radiolocation channel , and the data modulated with the Walsh channel code is extended by QPSK using a pseudorandom noise code (PN code), summed with the data of the other channels, and converted upwardly for transmission, preferably in accordance with the IS-95 standard (propagation, addition and upconversion not shown).
P1729 / 99MX With reference still to Figure 4, data transmitted via the fast paging channel is directly applied to a code of the Walsh channel designated for a fast paging channel, and then propagated, added and up-converted as described before. Preferably, a single data bit transmitted via the fast channel is modulated several times by the same Walsh code by effectively transmitting the bit several times. The data bit may be transmitted repetitively using a symbol repeater such as the symbol repeater 61 used for the complete radiolocation channel. In yet another embodiment of the invention, the rapid radiolocation channel can be retransmitted using the long code as it is done for the complete radiolocation channel. As will be apparent from Figure 4, the processing associated with the transmission of information over the rapid radiolocation channel is substantially less in duration and complexity than that associated with the complete radiolocation channel. Therefore, the amount of processing necessary to perform the reception processing of the rapid radiolocation channel is also substantially less, and therefore requires less energy than that required for the radiolocation channel.
P1729 / 99MX complete. While the reduced amount of processing performed by the rapid radiolocation channel increases the probability of error during the processing of any particular bit, other methods can be employed to reduce the effect of this increased error rate without substantially increasing complexity. The method includes transmitting the same bit several times or interpreting the low quality transmissions as positive radiolocation messages as described below. Figure 5 is a flow chart of the processing performed by a wireless terminal 10 in a standby mode when performed in accordance with an embodiment of the invention. The processing is preferably performed using a microprocessor controller by instructions of a memory program stored in the memory coupled to other integrated circuits and systems that are well known in the art (not shown). The processing begins in step 80 and in step 84 it is determined whether the assigned rapid paging interval has arrived, and if not, step 82 is performed again. If the assigned rapid paging interval has arrived, the wireless terminal 10 processes the rapid radiolocation channel in step 86. Properly, the P1729 / 99MX processing is performed using a significantly smaller subset of the signal processing circuitry contained in the wireless signal that is used to process the complete radiolocation messages. According to the transmission processing performed by the rapid radiolocation channel shown in Figure 4, the reception processing is preferably comprised of the down-conversion of the received RF energy, the propagation with the PN propagation code, and the demodulation with the assigned Walsh code. The resulting transient decision data is processed directly to determine the logical level transmitted. Referring again to Figure 5, in step 88 it is determined whether a rapid radiolocation message was received in step 86 based on the logical level of the detected data. If a rapid radiolocation message was detected, processing continues in step 90 as described below. If a rapid radiolocation message was not detected, it is determined in step 89 whether the signal quality during processing of the fast radiolocation channel was acceptable. If so, the wireless terminal 10 returns to step 82. If the signal quality was not acceptable, the processing continues in step 90 as described.
P1729 / 99MX later. The quality of the received signal can be determined by several well-known methods including determining when the reception power of the transmitted signal from the transmitter 50 drops below a threshold, or by determining when the signal-to-noise ratio of the pilot channel drops by below a predetermined threshold. When monitoring a complete radiolocation message when the quality of the received signal is not acceptable, the number of missed complete radiolocation messages due to undetected rapid radiolocation messages resulting from the unacceptable quality of the signal is minimized. If a rapid radiolocation message was detected, or the quality of the received signal was not acceptable, the wireless terminal 10 is activated, the additional decoding circuitry in step 90 and in step 92 processes the complete radiolocation channel during the assigned full radiolocation interval using the activated circuit set. The time when the rapid radiolocation interval and the complete radiolocation interval assigned to a particular terminal should be sufficient to allow activation of the additional decoding circuitry within the wireless terminal 10 after detection P1729 / 99MX of the fast paging message before the full paging interval is present. In step 94, the wireless terminal 10 determines whether the entire radiolocation message processed in step 92 was directed to it, based on the address contained in that message, and whether the set of decoding circuits within the terminal was not deactivated. wireless 10 in step 82 and step 84 is performed again. If the complete radiolocation message was addressed to the wireless terminal 10, processing for the corresponding communication begins within the wireless terminal in step 96, and the wireless terminal enters the wireless terminal. to the active mode in step 98. Figure 7 is a block diagram that provides a highly simplified illustration of the wireless terminal 10 when configured in accordance with one embodiment of the invention. The digital demodulator 302, block interleaver 304, lattice decoder 306 and control system 308 are coupled via the digital common bar, and RF receiver 300 is coupled to digital demodulator 302. During the standby mode, the control periodically activates the RF receiver 300 and the digital demodulator 302 to process the channels Pilot P1729 / 99MX and fast radiolocation. The RF receiver 300 down-converts and digitalizes the RF signals and the digital demodulator 302 performs the digital demodulation during a first duration generating the transient decision data for the channels that are processed. The control system 308 examines the transient decision data of the pilot channel to determine the quality of the signal and examines the fast paging channel to determine if a rapid paging message has arrived. If a rapid radiolocation message has been received, or the signal has been received with poor quality, the control system 308 activates the block interleaver 304 and the lattice decoder 306 and configures the digital demodulator to begin the processing of the radiolocation channel complete for a second duration that is longer than the first duration. The control system 308 then monitors the received data over the complete radiolocation channel for a complete radiolocation message directed to it, and if none is detected, it deactivates the block deinterleaver 304 and the lattice decoder 306 and continues in the same mode. wait. If a complete radiolocation message is detected, the control system 308 places the wireless terminal in the active mode P1729 / 99MX during which the associated communication is carried out. In still another embodiment of the invention, the rapid radiolocation channel and the complete radiolocation channel are combined in the same code channel. That is, the rapid radiolocation channel and the complete radiolocation channel are modulated with the same Walsh code. Within the same code channel, the rapid radiolocation channel and the complete radiolocation channel is logically distinguished by a predetermined time division scheme. For example, during some 80-ms intervals, rapid paging messages are transmitted, while during the other 80-ms intervals, messages of the complete paging channel are transmitted according to a predetermined slot allocation scheme. This implementation simplifies the reception and transmission process a bit because it only requires the modulation and demodulation of an individual code channel. But it will require a more significant modification to the existing IS-95 standard, and therefore, provides more compatibility with existing wireless communication systems that comply with IS-95. As will be evident from the description given above, the P1729 / 99MX radiolocate using a fast paging message with a minimum number of bits and that is transmitted over a minimally encoded channel, the present invention allows a wireless terminal to consume less power when it monitors the paging messages during the standby mode. The consumption of less power in the standby mode allows a wireless terminal to operate for a longer time in a given battery, thus extending the waiting time of that wireless terminal. Since wireless terminals are typically used in mobile telecommunications, it is often necessary to go for extended periods of time without recharging or replacing the battery of the wireless terminal. In this way, in order to provide increased convenience, and reduce the likelihood of erroneous radiolocation messages due to energy depletion, prolongation of standby time for a given battery size is highly desirable. Additionally, since rapid radiolocation messages are transmitted within a greatly reduced period of time, rapid radiolocation monitoring can be performed during active mode when a telephone call or other communication is being processed, in addition to the standby mode. This monitoring can be done by briefly suspending P1729 / 99MX the processing of the traffic channel to allow processing of the fast paging channel during the rapid paging interval. Since the fast paging interval is in the order of 5 ms, any lost data will typically not be lost or detected, and can often be recovered using early error correction (FEC) coding. Once the rapid paging message is received, the complete paging message can be received by further suspending processing of the traffic channel by the transmission of a signaling message to the controller of the base station, followed by processing of the paging channel. complete radiolocation. In this way, the ability to receive the radiolocation message during the active mode is improved by the use of a dual event radiolocation scheme described herein. In this way, a dual-channel method and system for radiolocating cell phones and other wireless terminals that reduces power consumption in the standby mode has been described. The prior description of the preferred embodiments is provided to enable any person skilled in the art to make use of the present invention. The various modifications to these P1729 / 99MX modalities will be readily apparent to those skilled in the art, and the generic principles defined therein can be applied to other modalities in use in the inventive faculty. Thus, the present invention is not intended to be limited to the embodiments shown herein, but to be in accordance with the broader scope consisting of the principles and new features described herein.
P1729 / 99MX

Claims (32)

  1. NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and, therefore, the content of the following CLAIMS is claimed as property; A method for radiolocating a wireless terminal in a wireless telecommunications system comprising: transmitting a rapid radiolocation message via a less coded channel; and generate a complete radiolocation message via a more coded channel. The method according to claim 1, wherein the rapid radiolocation message contains less information than the complete radiolocation message. The method according to claim 1 or 2, wherein the rapid radiolocation message is for notifying the wireless terminal to begin processing for complete radiolocation. The method according to claim 1, 2 or 3, wherein the rapid radiolocation message is comprised of a single data bit. 5. The method for radiolocalizing a wireless terminal from a set of wireless terminals, comprising: a) transmitting a message of P1729 / 99MX rapid radiolocation directed to a subset of the set of wireless terminals that includes the wireless terminal; and b) generating a complete radiolocation message identifying the wireless terminal. The method according to claim 5, wherein step a) is comprised of the step of transmitting the fast radiolocation message via a less encoded channel during a time slot assigned to the wireless terminal. The method according to claim 6, wherein step b) is comprised of the step of transmitting the complete radiolocation message during a second time slot assigned to the wireless terminal that occurs after the first time interval. The method according to claim 5, 6 or 7, wherein the rapid radiolocation message is transmitted over the less coded channel and the complete radiolocation message is transmitted over a more coded channel. The method according to claim 8, wherein the first channel is established via direct sequence modulation with a first channel code and the second channel is established via direct sequence modulation with a second channel code. The method according to claim 9, wherein the first channel code is a first code P1729 / 99MX of Walsh and the second channel code is a second Walsh code. The method according to any of claims 5 to 10, wherein the rapid radiolocation message has less information than the complete radiolocation message. 12. A method for locating the wireless terminal comprising: a) generating a rapid radiolocation message; and b) generating a complete radiolocation message, wherein the rapid radiolocation message contains substantially less data than the complete radiolocation message. The method according to claim 12, wherein the rapid radiolocation message is transmitted on the least coded channel, and the complete radiolocation message is transmitted on a more coded channel. 14. The method according to claim 12 or 13 further comprising the steps of: co-convolutionally coding the complete radiolocation message; propagate the direct sequence of the complete radiolocation message; and propagate the direct sequence of the rapid radiolocation message. 15. The method according to claim 12, 13 P1729 / 99MX OR 14 further comprising the steps of: adding error detection information to the complete radiolocation message; propagate the direct sequence of the complete radiolocation message; and propagate the direct sequence of the rapid radiolocation message. The method according to claim 12, 13 or 14 further comprising the steps of: interleaving the complete radiolocation message; propagate the direct sequence of the complete radiolocation message; and propagate the direct sequence of the rapid radiolocation message. The method according to any of claims 12 to 16, further comprising the steps of adding a time delay between when the rapid paging message is transmitted and when the direct paging message is transmitted. 18. The method according to any of claims 12 to 17 further comprising the steps of: receiving the rapid radiolocation message; activate the signal processing circuitry; Y P1729 / 99MX process a complete radiolocation channel using the signal processing circuit set. 19. The method according to claim 18, wherein the signal processing circuitry is comprised of a trellis coding system. The method according to claim 18 or 19, wherein the signal processing circuitry is comprised of a deinterleaver. The method according to claim 18, 19 or 20, wherein the signal processing circuitry is comprised of a cyclic redundancy check circuit. The method according to any of claims 12 to 21, wherein in the rapid radiolocation message is transmitted during a rapid radiolocation interval within a radiolocation channel, and the complete radiolocation message is transmitted during a complete radiolocation interval within of the radiolocation channel. 23. The method according to any of claims 12 to 22, further comprising the steps of: c) calculating a rapid radiolocation interval via the application of a P1729 / 99MX first key function to a MOBILE_ID of the wireless terminal; d) calculating a complete radiolocation interval via the application of a second key function to the MOBILE_ID, wherein the rapid radiolocation message is transmitted during the rapid radiolocation interval and the complete radiolocation message is transmitted during the complete radiolocation interval . 24. The method according to claim 23, wherein MOBILE_ID is XORed with a function of the system time. 25. The method according to claim 23 or 24, wherein step c) is performed via the application of a first key function to the time of the system as well as the MOBILE_ID. 26. A method for receiving a radiolocation message comprising the steps of: a) monitoring a rapid radiolocation channel for a rapid radiolocation message; and b) monitor a complete radiolocation channel when a rapid radiolocation message is received. The method according to claim 26, wherein the rapid radiolocation message is shorter than the duration of the complete radiolocation message. P1729 / 99MX 28. The method according to claim 26 or 27, wherein the fast paging channel is less coded than the co pap radiolocation channel. The method according to claim 26, 27 or 28, wherein the entire radiolocation channel is processed by the modulation with a first channel code, and the fast radiolocation channel is processed by the modulation in a second channel code. The method according to claim 29, wherein the rapid radiolocation message is monitored for a radiolocation channel during a rapid radiolocation interval, and the complete radiolocation message is monitored for the radiolocation channel during a complete radiolocation interval. The method according to any of claims 26 to 30, further comprising the steps of: activating the signal processing circuitry when a rapid radiolocation message is received, wherein step b) is performed using the set of signal processing circuits. 32. An apparatus for radiolocating a wireless terminal in a wireless telecommunications system, the apparatus P1729 / 99MX comprises: means for transmitting a rapid radiolocation message via a less coded channel; and a means for generating a complete radiolocation message via a more coded channel. P1729 / 99MX
MXPA/A/1999/011043A 1997-05-30 1999-11-30 A method of and apparatus for paging a wireless terminal in a wireless telecommunications system MXPA99011043A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US08865650 1997-05-30
US08890355 1997-07-09

Publications (1)

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MXPA99011043A true MXPA99011043A (en) 2000-08-01

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