MXPA97005595A - Architecture of installation of network identification information for messaging system that has erra capacity - Google Patents

Abstract

The present invention relates to network roaming information (NRI), which identifies a network (200) and a service area (210) within the network (200), a network address, is transmitted in a network (200) during a predetermined number of time segments of a signal, by means of which the signal is transmitted in consecutive cycles, each cycle comprising a number of consecutive segments. The installation of the NRI in the transmitted signal is predicted by a receiver such that the receiver can compute an eted time slot location of an NRI to be compared with the stored NRI. The installation of the NRI is done according to an algebraic relationship between the MODULE of the signal transmission frequency, the MODULE of the cycle order and the MODULE of a portion of the NRI, where N is a number between

Description

ARCHITECTURE OF INSTALLATION OF NETWORK IDENTIFICATION INFORMATION FOR MESSAGING SYSTEM THAT HAS ERRANT CAPACITY RELATED APPLICATION This invention is a continuation in part of US Patent Application No. 08 / 378.16 filed on January 14, 1995.

Field of the Invention This invention YES? It relates to messaging systems and more particularly to a messaging system that has the capacity for a receiver to err and receive messages in a multitude of coverage areas.

Background of the Invention In today's mobile society, we want t .. locatable, eg. by a selective call receiver. { pagers), wherever you travel, both locally near the home, and in more distant places in the same country or in the world.

A method and messaging system that is capable of adapting to roving portable communication receivers, e.g. pagers, between areas of coverage of the same service provider and in areas of coverage of different service providers.

Synthesis of the Invention The present invention aims at a system and method for a signaling protocol suitable for transmission of messages to a number of locatable receivers that is capable of adapting to roving receivers and of maintaining the performance of battery saving in the receivers by providing a scheme to allow that the receiver predicts the frequency of time segments of certain address information in a transmitted signal.

These and other objectives and advantages will become evident when the following description, taken together with the accompanying drawings, is used.

Brief Description of the Drawings Figs. 1-3 are time charts illustrating a signaling protocol in accordance with this invention.

Fig. 4 illustrates a structure of a frame information word according to the present invention.

Figs. 5 and 6 illustrate block information word structures in which unique simultaneous transmission identification information (SSID) is encoded.

Fig.7 illustrates a coverage area and divisions in zones according to the invention. Fig.8 illustrates a network and service area divisions according to the invention. Figs. 9 and 10 illustrate structures of an address word and a vector word, respectively, in which network errant identification information (NRI) is coded according to the invention. Fig.11 is a block diagram illustrating the installation of the local area identification information * ^ LID) and time information according to the invention. Fig.12 is a diagram in tables illustrating an installation configuration of the NRI information according to the invention. Fig.13 is a diagram in tables illustrating an example of the installation configuration of the NRI information according to the invention. Fig.14 is a diagram illustrating a scan sequence used by the receiver for channel identification during possible situations of frequency overlap. Fig.15 is a flow diagram that illustrates in general how a receiver detects SSID and NRI information. Fig.16 is an electrical block diagram of a selective call receiver according to the invention.

Fig.17 is an electrical block diagram of a transmitting station in a paging system according to the invention.

Detailed description of the invention The invention aims at a selective call communication system capable of delivering or transmitting messages to receivers that wander between coverage areas. An example of a selective call signaling system to which the present invention relates is described in US Patent No. 5,128,665. The full text and drawings of U.S. Patent No. 5,128,665 are incorporated herein by reference. The present invention, however, is in no way limited to a particular type of signaling protocol and is useful in many types of communication systems, a paging or messaging system is just one example.

With reference to Figs. 1-3, an example of a selective call communication system to which this invention pertains is shown. The signaling system shown comprises 128 frames, each frame numbered from 0 to 127. The frames are transmitted at 32 frames per minute and therefore a complete cycle of 128 frames lasts 4 minutes. One hour is divided into 15 cycles numbered from 0 to 14. It is a protocol of synchronous time segments linked to a universal time reference. Table 0 is synchronized to start at each hour so that the receiver can derive real time from the frame number and current cycle, thus providing the receiver with accurate time within the hour without the need for adjustment.

Moreover, the protocol supports multiple "phases" multiplied by time division, where for example, a data stream of 6400 bits per second (bps) is multiplexed by time division into four 1600 bps data streams. Such a signaling structure is described in U.S. Patent No. 5,168,493, the full text and drawings of which are incorporated herein by reference. Therefore, the general frame structure shown in Fig. 1 for the single phase shown in Fig. 1 is the same in each of the four phases.

Each frame comprises a portion of synchronism and several blocks. The synchronization portion comprises a portion of Sync 1 (Si), a word of frame information (FI) and a portion of Sync 2 (S2).

Each receiver is assigned a base frame in the set of 128 frames that appear in a radio frequency (RF) channel. A receiver can change battery life by more frequent delivery of messages if the monitoring of more than one frame is assigned per cycle. Once the receiver acquires synchronization with the radiofrequency channel, it expects to find its assigned frame within a very narrow window of time. The use of FM of 4 levels doubles the speed of data transmission per symbol (compared with the FM of 2 levels) which contributes to reduce the effect and errors of simultaneous transmission distribution and the effect of temporary differences of propagation between multiple signals within the receiver's reception spectrum.

As shown in Fig.3, the Sync 1 (SI) portion of each frame provides frame synchronization, symbol synchronization and indicates the speed of the rest of the frame. The frame information word (FI) carries 11 bits for the frame and cycle numbers, 5 bits for the indication of the phase multiplexed by time division of little traffic, 1 bit called Bit of Network Wandering Channel to indicate the presence of a service throughout the network with frequency support and other information. The Network Wandering Bit Network is used to trigger the recognition of certain roving network information that will be described along with Fig. 4.

The portion of Sync 2 (S2) provides the synchronization in the frame rate of the frame to allow the demiplexing and correct decoding of the blocks.

The Block Information Field (BI) is the first 1-4 words, called block information words, of the first interleaved block and contains information of frame structure and system, part of which is relevant to the present invention and it is explained in more detail from here on.

The address field (AF) starts directly after the block information words and consists of short addresses and long addresses. The vector field (VF) maintains a 1 to 1 relationship with the address field. The message field (MF) contains the message words specified by the vector field. IB represents free blocks that are not used and filled with appropriate bit patterns.

Fig. 4 illustrates the structure of the picture information word in more detail. The various parameters in the frame information word are defined as follows: C Cycle number (0-14) c3c2clc0 15 / hour f Frame number (0-127) f6f5f4f3f2flf0 128 / cycle n Network Wandering Channel Bit n = l indicates network support for errant and n = 0 indicates no network support for errant r Repetition Paging Indicator If r = l, t3t2tlt0 are reserved to indicate that a repetition format exists * If r = 0, t3t2tlt0 are indications of Little Traffic for each phase in a table t Definition that depends on the value of "r" A 3200 bits / sec. t3 = t2 and tl = t0 represents two phases in table A 1600 bits / sec. t3 = t2 = tl = t0 represents a phase in the table t = l indicates address field contained in block 0 t = 0 indicates address field extends beyond block 0 These indications give a first indication that the traffic is light and that all addresses are contained within block 0. x Normal 4-bit Verification Character Fig.5 illustrates an example of information word of block 1. The information word of block 1 has 2 bits "a" aOal indicating the beginning of the address field, 6 bits "v" v5v4v3v2vlv0 that define the beginning of the field of vector, 2 bits "c" clcQ indicating traffic overload in the following table (s), 3 bits V m0mlm2 indicating the number of high-order frame number to be masked and 4 bits "P" P3P2P1P0 indicating the number of priority addresses at the beginning of the address field.

Fig.6 illustrates an example of block information words 2,3 and 4. The Word Format Type is represented by the format bits f2flf0, s represents the data and x again is the normal 4-bit Verification Character.

Below is a table showing the bit pattern definitions for the f and s bits shown in Fig.6. According to the values of the bits f2flf0, the data bits sl3 -s0 have a particular meaning or application. When f2flf0 is set to (000), the sl3-s0 bits represent a 9-bit local area identification number (LID) (Í8-Í0) that identifies 512 possible LIDs and a 5-bit Zone number C4C3C2C1C0 that represents 32 Possible coverage areas associated with a particular LID. t2t? t0 Si3S12S ?? S? oS9S8S S6S5S S3S2S1So 000 Í8Í7Í6Í5Í4Í3Í2Í) .í0 C4C3C2ClCQ 512 Local IDs 32 Coverage Zones 001 iriamami od d3d2, d1dQ Y4Y3Y2Y] Y0 Day, Month, Year 010 S2S! So M5M4M3M2M? Mo H4.H3H2r.iH0 Hour, Min., Sec. 011 Reserved for future use 100 Reserved for future use 101 Z ^ Z, ^ Z ? ZiZ ^ Z? Í Z i- ZzZ? Z? ¡A3A2A1A0 Data, Message System 110 Reserved for future use 111 C9CBC7C6C5C4C3C2C1C0 T3T2T1 0 Country Code Indications Traffic Division When f2flf0 is set to (001) and (010), the data bit pattern sl3-s0 represents information of day, month, year, hours, minutes and seconds as shown in Fig. 7. EJ. The flflfO bit pattern (101) designates blank data bits sl3-s0, a system message A3-A0 and time zone information Z3-Z0.

Finally, the bit pattern f2flfQ (111) is important, which indicates a 10-bit Country Code c9-c0 and 4 bits called Traffic Division Indications, both described in more detail hereafter.

Follow the Country Codes, eg. , the Normal CCITT that is well known in the art. The 10-bit Country Code is provided to allow the reuse of LIDs in different countries, following the normal CCITT assignment rules. The Country Code information is useful for the non-subscriber receiver to facilitate a more efficient scan search by first identifying in which country the receiver is located.

With reference to Fig.7, the smallest division of a coverage area 100 is defined by a simultaneous transmission system identification (SSID). An SSID consists of and is uniquely identified by several identifiers: a LID, Zone, Country Code, Traffic Division Indications (TSFs) and Frequency. Each Zone 110 has a unique SSID. Therefore, if the user wishes to receive messages in more than one Zone, the receiver carried by that user would store each of the corresponding SSIDs. The Zones shown in Fig.7 do not need to be geographically next to each other.

In the example shown in Fig.7, there are 512 possible LIDs, each with 32 possible Zones. A "Zone" is a single simultaneous transmission area that may be associated with other areas of simultaneous transmission in a coverage area through a common LID. For example, a service provider is given the LID 123456789XXXXX. The service provider has the option to assign this LID to 32 different divisions of a coverage area or Zone, The northern part of a coverage area of the service provider may be Zone 1 and transmit 12345678900001, while the southern part is Zone 2 and transmit 12345678900010.

The Traffic Division Indications indicate the assignment of 4 groups of roving traffic to a frequency (channel) . Each wandering receiver that finds a frequency to carry a LID responds to only one of the 4 Indications of Traffic Division. When a receiver assigned flag is equal to 0, the receiver looks for another frequency with the same LID and the assigned flag is set equal to 1.

The SSID information is coded in two words: Word (000) 9 bits = 512 LIDs 5 bits = 32 Zones 2a Word (111) 10 bits = 1024 Country Codes 4 bits = Traffic Division Indications The Word, hereinafter called LID1, corresponds to the first word of information of Block (000) referred to in Fig.3 and the 2nd Word, hereinafter called LID2, corresponds to the word of information of Block (111).

The time and calendar information (block information words f2flf0 = 001, 010 and 101) when transmitted are defined as those shown in table 0 or otherwise in the first valid table following table 0. In a system with roaming capacity, the LID together with the Zone, Country Code and Traffic Division Indications occupy the second and third block information words in box 0. The fourth block information word carries the three words of information from time and clamber and are sent in the position of the fourth block information word in frame 0 in a rotating sequence of one word of block information at a time in 3 consecutive cycles. This allows the block information words 001, 010 and 101 to be updated 5 times per hour.

An advantage of this scheme is that the time and calendar information is sent without directions.

The bits A3-A0 define the type of message and a class of receiver for which they are intended, as shown in the following table. For example, all recipients should observe this message, recipients using SSIP frequency information should look only at this message and / or only receivers that are using network wandering information (NRI) (which will be described later) to close this channel should look at this message. You can also send instructions on the frequency to be used when changing the Traffic Division Indication and time zone information.

A3 A2 To A0 0 0 0 0 All messages 0 0 0 1 Local message 0 0 1 0 Wandering message 0 0 1 1 Wandering instruction 0 1 0 0 Time Zone -k -k -k -k 1 Reserved for future use When a system message is indicated, one more or is added to the end of the or field. A receiver decodes block 4 information and determines the type of instructions and which receivers should look at the message associated with this block information word. Once the receiver has determined that it should look at the message it processes the address field and the or field as normal but there will be one more or at the end of the or field. Only receivers that have instructions to look for a message will look at this or since all combinations of address / or will point to message words that are located after this or that is actually in the location of the first message word for the field of message. Up to this point, a certain group of recipients have been informed that there is a message, what kind of message to expect and where to look for this message. Once the receiver enters the message field it decodes the message and moves it according to the type of message.

An example of a system message is a greeting message transmitted to a recipient who is wandering in a coverage area outside of their home coverage area.

Another example of the utility of a system message is related to the Traffic Division Indications. When a service provider has two systems that have the same coverage area (ie redundant systems) or portions of overlapping coverage areas, and would like to move traffic from one system to another, the following process is followed.

A system message is sent as described above to inform the receiver that there will be a traffic change and that the traffic change information is a new XXXXX frequency. The receiver adds this new frequency to its sweep list. The receiver should move to the XXXXX frequency and look for an SSID or NRI assigned to this other frequency. In a subsequent transmission, which may be a month later or may be 1 minute later, the Traffic Division Indication is removed from a frequency and installed in the redundant coverage area system. The receiver detects that the roaming traffic is no longer supported on its channel and moves to the frequency where it was instructed to go through the message.

Once there, the receiver determines if the SSID or NRI and the Traffic Division Indication is correctly installed. When the SSID or NRI information stored in the receiver matches the corresponding transmitted information, the receiver remains on the frequency (and adds this frequency to its sweep list). When there is no match, the receiver returns to the frequency where it was originally to make sure it made an error. When that frequency no longer supports the roaming traffic of the receiver, the receiver begins to search for itself (sweeping the walk) a match of SSID or NRI.

Another way to handle the traffic division is for the system to take out the Traffic Division Indication and let the receiver find a new system by transmitting the SSID or ^ NRI of that receiver.

It should be understood from the foregoing that the same LID and Zone values can be used by the same provider or by other providers in other channels.

A sweep list, containing at least one SSID, is stored in each receiver. In each Zone, an SSID is transmitted in a predetermined number of frames, as will be explained hereafter together with Fig.11.

Turning now to Fig. 8, in the case where a receiver wishes to have coverage in a larger area, or receive messages in multiple frequencies, which would otherwise be defined by multiple SSIDs, a single identification information is used, in place of multiple SSIDs. This is called network errant information (NRIJ) A "Network" 200 is defined as a set of muncha Service Areas 210 and a Service Area 210 is a conglomerate of coverage areas 100 which is otherwise defined by the amount of S.SIDs Thus, in a simple case, a Service Area 210 shown in Fig.8 is the same as the coverage area 100 shown in Fig.7 and comprises multiple Zones.

An NRI consists of a network identification (NID), an Area dt? Service (SA), Traffic Division Indications and a 3-bit NID multiplier to expand the number of Unique Networks.

A Network can be formed through an agreement between several different service providers, or it can be a single service provider. In a Network, there are a number of Service Areas and in the example described here, there are 32 possible Service Areas within a Network, identified by a 5-bit pattern, but a Network can be defined as consisting of more or less Service Areas.

As shown in Fig.8, in each Service Area Zone, an SSID is transmitted and at least one, but possibly several, NRIs are transmitted as indicated by NI, N2, etc. Therefore, a Zone is potentially affiliated with multiple Networks or Service areas and would need to transmit the corresponding NRIs. The limits shown in Fig.8 illustrate functional limits and not necessarily geographic boundaries. However, no matter where they are geographically located, all Service Areas within a common Network are required to transmit the same NID sequence or network identifier. The individual Service Areas within a sdfí Network specified by the Area identifier of service.

Figs.9 and 10 illustrate how the NRI is encoded in the signal transmitted in each Service Zone. Fig. 10 illustrates a conventional binary coded hexadecimal address word 32-21, which is well known in the art. The first 21 bits d20-d0 of this word are joined to define an NID, 12 of whose bits are used to uniquely identify 4096 networks, as an example.

Fig.10 illustrates the vector word structure associated with the address word of Fig.9. The following table gives bit definitions associated with the vector word of Fig.10, ? t0 d1? d_ujdjdB dd5dildjd2djdo 00 C3C2C? Cob3b2b1boa3a2a? ao 3 Numeric characters with Short Address u.Oarflr.fp p.R Nnm ri.m -coia Long Address £ Vua_u) a5,. . . a0? > 12 useful bits to a Wandering Networks 01 S8S7S6S5S4S3S2SJ.S0S2S1S0 8 Sources plus 9 or 30 Unused Bits 10 S1SpRjjNjN4NjN2N.jNflS.iS.1Sx, 8 Sources, Number Message 0-63 Message Withdrawal Indication and 2 or 23 unused bits 11 Message Type Blank The bits V0V1V2 are used to specify the type of vector, eg. numerical, only in tones, etc. - When V0V1V2 are adjusted to a value corresponding to a particular type, eg. short message / only tones, this means that the 12 bits dO-dl l specify a Service Area, Traffic Dispatch Indications and Network multiplier. For example, aO-a4 define the Service Area (32 possible), a5 -a8 are the Traffic Division Indications and a9-all are Network Multiplier bits. The Network Multiplier bits allow 8 times 4096 more unique NIDs.

In certain circumstances, the network address has a system message bound to it, the 12 bits that define the additional NRI information reside in the message field and the vector otherwise operates as a vector that points to the system message in the message field, where the 12 bits described above also reside.

In each Service Area, the transmitted signal includes the NRI associated with the Service Area. The installation structure of the various parts of the NRI in the signaling protocol is shown in Figs. 12 and 13. In a receiver that is wandering in a network, a list is stored (frequency sweep frequency that includes a list of frequencies for which there is a high probability that an NRI match is obtained.The installation structure of Fig. 13 provides a way of predicting where the information can be found.In any case, when a match is not found from From the sweep list, the receiver searches through its entire synthesizer bandwidth.After the receiver closes in frame 0 at a particular frequency, a candidate frequency is quickly qualified or disqualified.

Fig.11 illustrates the installation structure of the SSID information in a four-phase expansion (multiplexed by time division) of the frame structure shown in Fig.l. When a single-phase system is used, all the information in phases A, B, C and D falls into phase A. When using a two-phase system, phases A and B fall together to form a phase and phases C and D fall together to form another phase.

As is known in the art, a time division multiplexed system with multiple phases A, B, C and D provides certain traffic management advantages for a service provider. A receiver capable of decoding the information from a single phase is assigned to a particular phase by the service provider at the time when the service was started. Some receivers are able to decode information from one phase at a time, but can move to a different phase. In this case, a service provider may initially assign a receiver to a particular phase, but may use the system messages described above to inform the receiver periodically that the messages will be transmitted in a different phase. Finally, some receivers are able to decode multiple phases and can consequently, shown by Fig.11, close in an allocated frame more quickly than a single-phase receiver.

In order to provide a roving service, all channels (frequencies) in a system that have roaming capacity are necessary to transmit a predetermined number of frames in their entirety. It is necessary that all errant channels transmit in their entirety a first predetermined number of frames, eg. Tables 0 to Table 7 with Table 0 aligned with the four minute time stamp. It is established, in this example, that tables 0-3 must be present and that these tables contain the words of LID LID1 and LID2 in the tables and phases as shown in Fig.11. It should be understood that the invention does not limit per se to tables 0-3 and that any number of other tables may be chosen as the "required" frames for transmission. Tables 0-3 are examples, of Tables 0-N.

Through the phases, LID1 and LID2 are run by u? So that the receiver assigned to a specific phase can determine its presence of desired SSID in the minimum amount of search time in each channel and to balance or distribute general information between the phases.

The installation structure shown in Fig. 11 provides a known time position to allow rapid processing of the candidate frequencies when the receiver is wandering. If the wandering decision can be made on the basis of exclusively LIDs, then 4 channels (tables 0 -3) can be processed every minute frame. Since frames 0-3 must be present, a fast sweep over an extensive bandwidth is performed using a symbol rate detection to identify channels with wandering capacity, LID2 is transmitted only in each phase once per cycle and LID1 is transmits every four frames, once in each phase (in at least squares 0-7).

For systems that use only SSIDs for roving coordination between ^ zones within a coverage area (service area), (without NRIs for roaming throughout the network) the agent or the 4 required frames is acceptable (tables 0-3). In this case, all transmitted frames are required to carry the word of information of block 000 and the mandatory tables 0, 1, 2 and 3 are necessary to carry words of information of block 000 and 111. The roving channels are identified during the mandatory time frame. During the rest of the cycle, any received frame is examined and removed if the SSID does not match. However, the absence of the protocol in any frame except box 0, 1, 2 or 3 can not be used to disqualify a channel, therefore, during a "fast sweep" through the bandwidth procedure, a pager can look for the signal in the protocol in Tables 4-127 and if the signal is detected in the protocol, the pager examines the block information word 000; if there is no match, the channel is deleted. The channels identified in said "rapid barri-do" process during the mandatory tables that can not be detected in tables 4-127 are examined in table 0, 1, 2 or 3 in order to determine the SSID.

"T" refers to the optional presence of three information words sent in table 0 on a rotating basis to indicate time and calendar information, as described above. The block information words of type "T" are sent in the whole of the 4, 2 or 1 phase according to the speed of operation of the system. It takes 3 cycles to completely renew a receiver with a complete set of time and calendar information (5 updates per hour). The time / calendar instructions are optional, but when they are carried by the system, they are necessary to follow the rotating pattern of a selection in each cycle. This format provides a known time / calendar position to allow a receiver to quickly process the candidate frequencies when it is. wandering. The rotary sequence can be changed so that a block information word format "T" 101 is used to send a roving system message when necessary.

In terms of LID installation standards, the present invention aims at a method for transmitting messages to a number of receivers to which it can be directed, the method comprises the following steps: dividing a coverage area into a number of zones; assigning to each coverage area a coverage area identifier comprising at least one area identifier? cal and a zone identifier such that the local area identifier is common to the entire coverage area, the zone identifier to identify an area within a coverage area; storing in at least one receiver to which one has subscribed to receive messages in at least one particular network a coverage area identifier associated with the at least one particular coverage area; generating a signal for transmission in each zone, the signal includes at least one identifier of coverage area corresponding to an area within a coverage area, the signal comprises a number of consecutive cycles of time, each cycle of time comprises a number of consecutive time segments, the coverage area identifier is located in the first predetermined number of timeslots of the signal; and transmit the signal in each zone.

Turning to Fig.12, an installation architecture for NRI information will be described which is useful in the connection with the roaming coordination throughout the network. It is necessary that all NRIs supported in a channel appear at least once during a first predetermined number of frames, eg. the boxes 0-7. For the shared channel operation, the providers of the service that share the channel agree to support the NRI installation rules of each one in tables 0-7. This allows the presence of more than one service provider in the channel. N1-N10 in Fig.12 represent 10 different NRIs.

It is necessary that all NRIs supported in the channel appear at least once during frames 0-7. It is necessary that the NRIs also appear in any of the 128 frames in which the calculations determine that they appear.

An expected and predicted position for an NRI is determined by the following set of rules: (a) Each frequency or channel transmitted on a network is represented by a number on the 0-7 scale. M = Module8 of Integer Number [Freq kHz / Spacing of channel kHz] (b) N = Module8 of NID (equal to the 3 least significant bits (c) C = cycle number (0-15); and (d) Table expected = F = Modulp8 of [N + M + C], According to these gifts, it is possible to search 8 consecutive frequencies for the same NRI in the 15 second period (8 frames) at the beginning of each 4 minute time period. The phase chosen to carry the NRI is the same phase as the one carried by the LID. This also causes the NRI to run one frame in each cycle which alleviates possible "shadow" problems in the case of a receiver located where two systems overlap. This installation sequence has a lower "general" NRI for cases where the channel carries less than 16 NRIs.

Generalizing, the NRI installation rules involve the installation of NRI in one of a first predetermined I number of frames and provide a predicted frame position using the modulol arithmetic based on the transmission frequency, 3 least significant bits of the portion of NID of the NRI and the cycle number (0-15), Fig. 13 illustrates an example in which 10 NRIs, represented by the numbers 1-10, are carried on a channel with mixed traffic or without traffic after frame 7.

An example of how a pager predicts an expected frame is described below: Network ID (NID stored in the pager code) = 2,008,123 (with the same result if the value is used in the air). * Frequency to be inspected 885,375 , 125 Khz (frequency not necessarily real, but used for this example) Channel spacing in this RF band = 25 Khz FLEX Cycle number present = 13 M - Channel number 885.375,125 / 25 = 35.415,005 Whole Part = 35.415 Module 8 (35.415) = 7 M = 7 N Network Address Number Module 8 (2,008.123) = 3 N = 3 C Number of Cycle Mod 8 = Module 8 (13) = 5 Expected Table F = Module 8 (7 + 3 + $) = Mod 8 (15) = 7 Therefore, the pager expects his NID to appear in this channel in Table 7 during Cycle 13. It will also appear in those boxes in which Module 8 (Frame #) = 7 if they are transmitted. To determine in which frame out of the first N frames NRI is present, the location of the NRI within the first 8 frames is known and its location progresses with precession (or is run by a higher frame) in later cycles. Consequently, the expected location of the frame can be determined in a subsequent cycle based on a known position in a previous cycle.

The receiver determines which cycle is being transmitted once it is closed in a channel and it is determined that the network bit is set. Starting from the frame information word in a frame, the receiver determines the cycle number of the current cycle being received, as explained above together with FIG. 4. Therefore, the calculation of the expected table in the current cycle and in the successive cycles is carried out, remembering that the expected table is known in a cycle, its precession is carried out in a table in subsequent cycles. Consequently, the expected table outside the first 8 frames can also be determined so that the receiver can locate and decode an NRI -out of -the mandatory tables 0-7 ^ In summary, according to one aspect, the present invention aims at a method for transmitting messages to a number of receivers, the method comprises the following steps: dividing a network into a number of service areas, each service area comprising at least minus one zone; assign to each network a roving network identifier comprising at least one network identifier and a service area identifier in such a way that the network identifier is common to the entire network, the service area identifier for identifying an area of service within a network; storing in at least one receiver to which one has subscribed to receive messages in at least one particular network a network identifier associated with the at least one particular network; generating a signal for its transmission in each zone, the signal includes at least one errant network identifier corresponding to a network that includes a service area corresponding to that zone, the signal comprises a number of consecutive cycles of time, each cycle of time comprises a number of consecutive time segments, the network errant identifier is located an ordered time segment based on an algebraic relationship between a signal transmission frequency, an order of a time cycle and a binary representation of at least a portion of the network errant identifier; and transmit the signal in each zone.

Are the LID installation rules and the NRI installation rules added? together in certain areas, therefore the present invention also aims at a method for transmitting messages to a number of receivers, the method comprises the following steps: dividing a network into a number of service areas, each service area comprising at least one coverage area, and each coverage area comprises 1Q least one area; assign to each network a roving network identifier comprising at least one network identifier and a service area identifier in such a way that the network identifier is common to the entire network, the service area identifier for identifying an area of service within a network; assigning to each coverage area a coverage area identifier comprising by lp minus a local area identifier and a zone identifier such that the local area identifier is common to an entire coverage area, the zone identifier for identify an area within a coverage area; storing in at least one receiver to which one has subscribed to receive messages in at least one particular network a roving network identifier associated with the at least one particular network; storing in at least one receiver to which one has subscribed to receive messages in at least one particular coverage area, at least one particular coverage area identifier associated with the at least one particular coverage area; generating a signal for its transmission in each zone, the signal includes at least one errant network identifier corresponding to a network that includes a service area corresponding to that zone and the signal includes a coverage area identifier corresponding to an antenna of coverage that includes that zone, the signal comprises a number of consecutive cycles of time, each cycle of time comprises a quantity of consecutive time segments, the errant network identifier is located in an ordered time segment based on an algebraic relationship between a signal transmission frequency, an order of a time cycle and a binary representation of at least a portion of the network errant identifier and the coverage area identifier is located in at least a first predetermined number of segments of ordered times of each time cycle; and transmit the signal in each zone.

Fig.14 illustrates a frame shift mechanism that allows a receiver to bar frequencies in all frames that are run from its identified home frame. This frame shift method is useful in situations where a receiver is mounted in an area where there are two or more possible matching frequencies in the same coverage area. In order that a match can be achieved at any of the possible frequencies, for each frequency whose coverage is desired, a frame is chosen in which the receiver can combine the SSID information, which is different from the frames for the other frequencies. For example, as shown in Fig.14 / the box chosen in each frequency runs a box. Other tables can be chosen. Consequently, the receiver can detect all SSIDs since each one is assigned to a different frame in the cycle.

Turning now to Fig.15, a method by which a receiver decodes a message will be described. From the beginning, it should be understood that there is a variety of wandering receivers according to the invention, including single frequency receivers and sintered frequency receivers that can be closed at any frequency in a predetermined bandwidth. Also, both types of receivers can be fixed phase, variable phase or multi phase.

Regardless of the type of receiver, when entering a new area in which the receiver has yet to lock on a signal transmitted in accordance with an established protocol, it is likely that from the last reception session of messages the receiver has a approximation of the appearance of table 0 in some frequency. The accuracy of the approach depends on the crystal oscillator of the receiver.

In step 3Q0, the receiver attempts to detect energy in the protocol at the last frequency in which it operates. When the receiver has a subscription to SSID, the procedure continues on the right side of the flowchart. When the receiver has a network coverage subscription, the procedure goes to the left side of the flow chart- In step 310, once the 0 frame of a cycle is found, the receiver can detect and compare the encoded SSID information in the transmitted signal with its stored SSID information. This process is carried out in accordance with the installation rules described in conjunction with Fig.11. When a match is found co or ε indicates in step 320, the receiver can locate its assigned frame to decode the message (s) addressed to it in step 330.

However, if the SSID in the transmitted signal does not match the SS * SSID stored in the receiver (justifying the current frequency of the receiver) then in step 340 the receiver switches to another frequency, if it is capable of doing so. When the receiver is a single frequency receiver, it can not tune to another frequency and enters the mode out of time and / or optionally a message from the receiver indicating its inability to receive messages at the current location of the receiver is displayed on the screen.

When the receiver has only NRI information stored in it, then, from step 3Q0 the procedure goes to step 350 and looks for an NRI match, taking into account the NRI installation rules of Fig.12 or Fig.13. When a match is found as indicated in step 360, the receiver locates his frame by grabbing and decoding his messages in step 370.

However, in the case where a match is not found in step 360, in step 380 the receiver tunes to another frequency using the recent list of frequencies where matches have previously been found. When that list does not exist in the receiver, then the receiver begins to sweep its band to store energy in the protocol and the process is repeated from the When a single frequency receiver is credited to a network coverage, then if no match is found in step 350, a message is displayed on the receiver that the user has left the coverage area, the receiver is not functioning correctly , or the service provider is not transmitting information on that frequency. An out of time period starts and the process is repeated some time later in an attempt to find an NRI match.

Below is an example of a sweep list. Generally, the first entry in the list is the last frequency and the associated SSID or NRI in which the receiver was closed. Then, a list of the SSIDs is made and finally, a list of NRIs with an associated frequency is made. Therefore, a receiver attempts to close on at least one frequency and associated SSID or NRI in which the messages are received and then proceeds through the SSID information and finally the NRI information, FREQUENCY SSID NRI Frequency 1 NID1 Frequency 2 SSID2 Frequency 5 SSID3 NID1 Frequency 3 NID1 Frequency 4 NID1 Frequency N SSIDN NID1 Fig.16 shows an example of electrical block diagram of a receiver 400 and particularly a selective call receiver according to the present invention. The transmitted coded message signals are received by an antenna 402 which splices with the input 403 of the receiving portion 404. The receiving portion 404 is preferably an FM receiver. The received encoded message signals are processed by the receiving portion 404 in a manner known in the art, and provided at the output 405 as a stream of binary information. The output 405 splices to the input / output port (1/0) 406 of the microcomputer 408. The receiving portion 404 optionally includes a signal indicating means of received signal (indication of received signal strength) 438 which also connects to the I / O port 406 of the 4Q8 microcomputer.

The microcomputer 408, represented for example by a Motorola MC68HC05 series microcomputer, fulfills a variety of functions, including decoding binary information. The microcomputer 408 includes a CPU 410, an opener 412, a timer counter 414, free access memory (RAM ^ 416, read-only memory (ROM) 418 and alarm tone generator 420. The CPU 410 controls the operation of the receiver 400 and processes the received coded message signals The oscillator 412 provides the timer for the operation of the CPU 410 and provides the timer for the timer counter 414. The oscillator 414 is controlled by a crystal, not shown in the diagram. slot identification and transmission channel and the paging addresses are stored in the code socket 422, which is a programmable read-only memory, eg an electrically erasable programmable read only memory (EPROM). NRI information is also stored in the code socket 422. RAM 416 is used to store code-taking information when the receiver 400 is activated in and to store messages when they are received. ROM 418 contains the factory elements that control the operation of the microcomputer. Factory elements include programs to control the decoding of transmission slot identification information, channel identification information, receiver address *, lists and receiver sweep frequencies, NRI information, SSID information and other functions of the receiver. The alarm generator 420 generates an audible alarm signal after the reception of the message.

When the 4Q0 receiver is initially turned on, the microcomputer 408 functions as a synchronization means, which allows the receiver 400 to synchronize the assigned transmission slot, after which the receiver detects information in the 0 frame and synchronizes the transmitted signal. The microcomputer 408 also functions as the decoder for decoding channel identification information, LID information, NID information and pager address information. The microcomputer 408, together with the frequency synthesizer 424, functions as a channel selector means 426 used to control the power monitor, providing a battery saving function for the receiver 400.

The. Fig.17 shows an example of a transmitting station 500 useful in accordance with the present invention. The transmitting station 500 comprises a paging terminal used to enter messages originating in a home or local area with respect to a receiver, as indicated in 504, or the messages are for the receiver that is wandering outside the local * area, as indicated in 506. The messages for the wandering receiver that originate outside the home or local area of the coverage area of a receiver is transmitted to the paging terminal 502 by a cable interconnection with a paging terminal in the home or local area, for example a dial or cable telephone line, or by means of an RF signal for example a satellite receiver.

The messages entered in the busphone terminal 502 are processed for transmission in the format or signaling protocol described above and in the aforementioned patent, or in another signaling protocol. The messages are placed on hold according to the frame to which a receiver is assigned. The output of the paging terminal is spliced with an RF transmitter 508 for transmission over an antenna 510. It will be appreciated that the paging terminal 502 optionally controls more than one transmitter. , for ex. in a wide area simultaneous transmission system, and that the synchronization of multiple transmitters in a simultaneous transmission system is provided. Various LPS, methods to synchronize the transmitters are available, eg. those described in U.S. Patent No. 4,718,109 to Breeden et al.

In addition, in order to provide global synchronization of the transmitters with frame 0 as described above, a synchronization module 512 is spliced with the paging terminal 502. The synchronization module comprises a global position system (GPS) receiver 514 and a timer module 516, which together with another allows the paging terminal 502 to determine an exact appearance of the square 0. Instead of a GPS receiver 514, another normal time signal is monitored by suitable monitoring devices.

It should be understood that although the invention was described in connection with a particular signaling protocol, the invention is useful with any synchronous signaling protocol.

The foregoing description is only an example and in no way attempts to limit the present invention except as set forth in the claims that follow.

Claims (10)

1. A method for transmitting messages to a number of receivers, the method comprises the following steps: dividing a network into a number of service areas, each service area comprising at least one area; assign to each network a roving network identifier comprising at least one network identifier and a service area identifier in such a way that the network identifier is common to the entire network, the service area identifier for identifying an area of service within a network; generating a signal for its transmission in each zone, the signal includes at least one errant network identifier corresponding to a network that includes a service area corresponding to that zone, the signal comprises a number of consecutive cycles of time, each cycle The time comprises a number of consecutive time segments, the network errant identifier is located in an ordered time segment based on an algebraic relationship between a transmission frequency of the signaling an order of a time cycle and a binary representation of at least a portion of the network errant identifier; and transmit the signal in each zone.

2. The method of claim 1, wherein the step of generating comprises locating all the errant network identifiers within a first predetermined number of time segments in a cycle for each frequency of transmission of a signal in a zone.

3. The method of claim 1, wherein the step of generating a signal for its transmission comprises locating the network errant identifier in a particular one of the N time segments, where N is equal to a predetermined enterp number representing a predetermined number of segments of time, the particular one of the N time segments is determined by a mathematical operation and module N of a sum of a number of c closes representing the order £ l time cycle, the N module of a whole number represefytation of the frequency of transmission of the signal and the module N of a predetermined number of the least significant bits of the binary representation of the network errant identifier.

4. The method of claim 1 wherein each service area comprises at least one coverage area., And each coverage area comprises at least one zone, the assigning step also comprises assigning each coverage area an area identifier of coverage comprising at least one local area identifier and a zone identifier such that the local area identifier is common to the entire coverage area, the zone identifier for identifying a zone within a coverage area; and the step of generating a signal for its transmission also comprises locating a coverage area identifier corresponding to a zone within n coverage area in at least a first predetermined number of time slots ordered from each time cycle.

5. A selective call receiver comprising: a receiver circuit for receiving a transmitted signal and generating output signals, the transmitted signal includes a roving identifier of network and is composed of a number of consecutive cycles of time, each cycle of time comprises an amount of consecutive time segments; a control circuit coupled to the receiver circuit and responsive to the output signals of the receiver, the control circuit comprises a memory for storing a particular network wandering identifier associated with ppr lp minus a particular network in which the selective call receiver is subscribed to receive messages, the particular network errant identifier also comprises an address associated with the selective call receiver to designate messages for the selective call receiver, a processor circuit for decoding the output signals from the receiver circuit in accordance with a control program, the processor circuit is programmed by the control program to: determine an order of a time cycle of a transmitted signal received by the receiver circuit; determining an expected time segmentP of the errant identifier and particular network in the signal transmitted by an algebraic relationship between a transmitted frequency of the transmitted signal received by the receiver circuit, an order of a time cycle of the transmitted signal received by the circuit receiver, and a binary representation of po? at least a portion of the errant network identifier stored in memory of the control circuit; and decoding the particular network errant identifier in the expected time segment of the transmitted signal and recovering a message in the transmitted signal associated with the address of the selective call receiver.

6. The selective call receiver of claim 5 which also comprises a frequency synthesizer circuit spliced with the receiver circuit to change a tuning frequency of the receiver circuit, where the processor is also programmed by the control program to respond to the division indications. of traffic in the transmitted signal to cause the frequency synthesizer to change the frequency of the receiver circuit so that the selective call receiver receives messages transmitted by a signal transmitted on a different transmission frequency.

7. A method for transmitting messages to a number of receivers to which messages can be directed in a multiplicity of coverage areas, each coverage area adapts the transmission of messages to at least one receiver, the method comprising the following steps: dividing coverage area in a number of areas; storing in each receiver at least one set of identification information, area and coverage, a set of coverage area identification information including a coverage area identifier to identify at least one coverage area, at least a zone identifier for identifying at least one area within the corresponding coverage area, and a frequency identifier for identifying a frequency at which the receiver receives message information in a corresponding coverage area; transmitting a signal in each zone of each coverage area in at least one transmission frequency, the signal includes a coverage area identifier associated with the coverage area, a zone identifier corresponding to an area within the coverage area and a message for at least one receiver in the area; and in a receiver, receiving the signal transmitted in a coverage area where the receiver is located if the frequency of transmission of the signal corresponds to the frequency identifier stored in the receiver, decoding the signal to the coverage area identdpr and to the identifier of zone in the transmitted signal to determine whether the coverage area identifier and the zone identifier stored in the receiver match the coverage area identifier and zone identifier in the transmitted signal and decode the transmitted signal to retrieve a message addressed to the receiver if coincidence is determined.

8. The method of claim 7 wherein the coverage identification information also comprises traffic division indications indicating to a receiver that a message for a receiver is transmitted by a signal at a forward transmission frequency.

9. The method of claim 8 / wherein the step of transmitting comprises transmitting the signal in cycles, each cycle comprising a number of consecutive time segments, wherein the identifier of coverage area and the zone identifier are contained in certain predetermined of the quantity of time segments.

10. A base station for use in a messaging system comprising: terminal means for receiving messages and for encoding the messages in a signal for transmission in at least one zone, the signal includes at least one errant identifier of the network corresponding to a network, a network comprises a number of service areas, and each service area comprises at least one zone, the signal comprises a number of consecutive time segments, the network errant identifier is located in a segment of ordered time based on an algebraic relationship between a signal transmission frequency, an order of a time cyclip and a binary representation of at least a portion of a network errant identifier.