HK1025198B - Selective call device and method fro battery saving during information services - Google Patents

Description

Selective call device and method for saving battery during information service

The technical field is as follows:

the present invention relates to communication systems, and more particularly to a method of saving battery power in a selective call device during information services.

Background art:

conventional selective call devices, such as receivers and/or transmitters, may often receive messages from more than one signal source. The signal sources are usually distinguished from each other by address information associated with each message. When the address information is associated with, or matches, a predetermined address in the selective call device, the selective call device receives and stores the message from the particular information source.

Modern selective call services or service providers are able to periodically transmit various types of data including information services, such as stock market, weather, sports, news or other information, to subscribed selective call devices (receivers or transceivers). Soon, it is likely that hundreds of information services are broadcast to the selective call device. As it rapidly expands, the number of information services available easily exceeds the amount of information that a selective call device can successfully receive or search for to find out the information to which it has subscribed before the battery life of the selective call device is consumed (exhausted or reduced).

The invention content is as follows:

therefore, there is a need for a method that enables a quick determination by a selective call device to conserve battery life when the information service being received is not intended for the selective call device.

According to one aspect of the present invention, there is provided a selective call device, comprising: a receiver for receiving a selective call signal including a device address and at least one topic sub-address indicating subscription information therein; an address correlator for correlating said device address in the selective call signal to determine whether the selective call signal is directed to the selective call device; a decoder responsive to the address correlator for decoding the topic subaddress if the selective call signal is directed to the selective call device and the selective call signal has the topic subaddress; and a battery saver coupled to the receiver for initiating battery saving when the selective call signal is not directed to the selective call device and for initiating battery saving when the selective call signal is directed to the selective call device but does not include the topic sub-address therein.

According to another aspect of the present invention there is provided a method for battery saving in a selective call device comprising the steps of: receiving a communication signal including therein at least one device address and at least one topic sub-address indicating a subscription information service; determining whether said communication signal is directed to said selective call device based on said device address; initiating a first battery saving procedure if said communication signal is not directed to said selective call device; decoding said communication signal if said communication signal is directed to said selective call device; and if the topic sub-address is not decoded to indicate that the subscribed information service does not exist, initiating a second battery saving procedure.

Description of the drawings:

fig. 1 is a circuit block diagram of a selective call system for providing an information service according to a preferred embodiment of the present invention.

Fig. 2-5 are timing diagrams illustrating the transmission format of the signaling protocol employed by the selective call system of fig. 1 in accordance with a preferred embodiment of the present invention.

Fig. 6 is a circuit block diagram of a selective call device according to a preferred embodiment of the present invention.

Fig. 7 is a flowchart illustrating steps by which the selective call device of fig. 6 receives an available information service.

The specific implementation mode is as follows:

fig. 1 shows a block circuit diagram of a selective call system (or radio frequency communication system) for generating and transmitting (or broadcasting) a selective call signal (or communication signal) including a plurality of information services according to a preferred embodiment of the present invention. The functions of selective call system 100 are preferably performed in software, such as a MODAX 500 selective call terminal manufactured by Motorola, inc. Typically, a user may send a message using telephone 102 to initiate transmission of a selective call message. As is well known, telephone 102 is coupled to selective call system 100, and in particular to base stations and base sites, through telephone network 104, the operation of selective call system 100 being well known to those of ordinary skill in the art. Likewise, a computer/modem 106 is also coupled to the telephone network 104 for entering information, such as alphanumeric or numeric messages. The telephone network 104 is coupled to a message receiver 108. the message receiver 108 typically receives messages from the public switched telephone network 104 to be transmitted (broadcast) to at least one of the plurality of selective call devices 130.

According to the preferred embodiment, the plurality of information services 140 and 152 are preferably coupled to a telephony interface network that is coupled to the processor 109 via the message receiver 108. Those skilled in the art will appreciate that the plurality of information service providers 140 and 152 may be received as radio frequency signals via an antenna.

When the base processor 109 receives information that is periodically transmitted as update data, the information is encoded as a message in the form of a selective call signal (or communication signal). In particular, a processor 109 coupled to the message receiver 108 determines the appropriate protocol, preferably FLEX^TMProtocol and address to encode information traffic. If the processor 109 determines that the message is to be sent via another signal format, it is passed to one of another protocol generator 116, which may include other protocol generators known to those of ordinary skill in the art. When the processor determines to pass FLEX^TMWhen the protocol transmits information traffic and any messages, the information is encoded and stored in a frame queue buffer 110, which buffers the informationThe buffer 110 has a queue (FRAME 0-N queue) of corresponding FRAMEs of the signal, and the corresponding number of FRAMEs N is 128 according to the preferred embodiment of the present invention. A predetermined frame Identification (ID) of the selective call device 130 corresponding to the message is determined and the message is stored in a corresponding frame queue. The capacity analyzer and frame ID/cycle generator 112 determines the order of frame IDs to be transmitted and analyzes the capacity of each frame to determine a cycle value to be used. The capacity analyzer 112 is also responsive to other protocols being transmitted. For example, if the expected frame occurrence is replaced by transmitting one of the other protocols (reducing the frame's capacity), the capacity analyzer 112 may interpret this by a determined cycle value. The bit and frame sync generator 118 synchronously generates bit and frame sync signals. Message formatter 114 determines the frame that will include the information in response to the addresses of selective call device 130 and the frame queue. The message is then formatted for transmission. The transmitter 120 receives signals from blocks 118, 114 and 116 and modulates and transmits radio frequency selective call signals via antenna 122 to the selective call device 130 in a manner well known to those of ordinary skill in the art.

Referring to fig. 2-5, timing diagrams of a signaling protocol according to a preferred protocol for selective call messages are shown in accordance with fig. 1. Referring to fig. 2, the selective call protocol is preferably encoded in accordance with the FLEXTM protocol in a number, preferably one hundred twenty eight (128), of message packets or frames 200. The duration of each frame 200 is preferably 1.875 seconds and preferably a basic data rate of 6400 bits per second. It should be understood, however, that other data rates may be used, including the use of multiple data rate capabilities.

Referring to fig. 3, each FRAME includes a bit sync signal 302, preferably a 32 bit 1, 0 alternating pattern, followed by FRAME SYNC #1 signal 304, preferably having a predetermined 32 bit word with 32 bit inversions, and a FRAME INFO signal 306, preferably a 32 bit word having 21 variable information bits containing information such as the number of cycles and the number of FRAMEs. BIT SYNC signal 302 provides BIT synchronization to selective call device 130, while FRAME SYNE #1 signal 304 provides frame synchronization and includes a signal indicating the data rate of the message information.

The FRAME INFO word 306 is followed by FRAME SYNC # 2308. FRAMESYNC # 2308 is followed by a block information word signal 310 that includes information such as a priority address number, the end of the block information field, and the vector start field. The codeword for each frame 200 is preferably encoded as a 31, 21 Bose-Chaudhuri-Hocquenghem (BCH) codeword with 21 information bits and 10 parity bits generated according to well-known BCH algorithms. An additional even parity bit extends the word into a 31, 21 code word. The address is located in block 312, the vector pointing to the message is located in block 314, and the message is located in the remaining block 316. Typically, all address signals within the frame are located in the first portion 312 and information or message signals are located in subsequent portions of the block 316. How to find the address 312 in the first portion and the message information 316 in the second portion of the frame 200 is well known to those skilled in the art. Words 310 and 316 are shown in the vertical direction to indicate that the words may be interleaved to improve the resistance of the transmission to burst errors. It will be appreciated by those skilled in the art that interleaving may be modified or eliminated.

Referring to fig. 4, the message information word 316 is illustrated in more detail in accordance with a preferred embodiment of the present invention. The information service 140 and 152 are encoded in a message information word 316 for transmission to the selective call device 130. In particular, the application identifier 402 identifies the type of information, for example, in this case, the application identifier 402 identifies the information service being transmitted as opposed to a numeric or alphanumeric selective call message. The application identifier 402 may also identify applications other than information services. Alternatively, the absence of the application identifier may indicate that the message or message is a normal selective call message.

The application identifier 402 is followed by a command number 404. The command number 404 identifies (or describes) the topic of how the information service is transmitted. For example, the command number identifies the topic for which the information service is transmitted according to one of two preferred methods, (1) a topic range method, represented by, for example, a "000" command number, including a range of information topics, e.g., as first and last topics (or from first topic to last topic); or (2) a itemized topic method, represented by, for example, a "001" command number, including each topic transmitted individually. As shown, the range method of FIG. 4 shows the title start sub-address 408 and the title end sub-address 410 as the ranges. Those skilled in the art will appreciate that the title end sub-address can comprise an offset from the title start sub-address or the actual title end sub-address without departing from the scope of the invention disclosed herein. Nonetheless, the title offset, i.e., the range method that can be encoded, has fewer bits than the title address. The information service or the topic of each information service is preferably specified by a unique number to facilitate correlation between topics and information services. The header length 406 identifies the beginning to the end of the topic address field, e.g., blocks 408 through 410. The selective call device 130 or other receiving device that does not take into account battery savings may skip the topic address using the header length in order to find the information or message in the information data block 412. The range of information headers is preferably transmitted as a topic start address (sub-address) 408 and a topic end address 410, the topic start address 408 specifying, for example, a first or start address to be transmitted, and the topic end address 410 specifying, for example, a last (or end) address (sub-address) in the transmission. Thus, by specifying the information topic addresses, the topic start sub-address 408 and the topic end sub-address 410 (topic range) in a sequential manner, e.g., in an ascending or descending order of unique identifiable numbers, identifies the possible information services included within a transmission for a given topic range. It is to be understood that the topic addresses can be transmitted in any order or non-order. Since each information topic address is specified by a unique number transmitted in either ascending or descending order, the selective call device 130 decoding the topic range can quickly determine whether the transmission includes the information service to which it is currently subscribed. When the topic address ranges 408, 410 do not include the unique topic addresses of the information services subscribed to by the selective call device 130, the selective call device can be immediately turned off, saving battery. After the topic ranges 408, 410 (topic start and end subaddresses), the full address, command and information data 412 of the information service is transmitted.

Thus, selective call device 130 can determine whether to receive the transmitted information service after decoding the topic start and end addresses (topic ranges) 408, 410. The selective call device 130 will conserve battery if its subscribed information services are not within the scope of the topic start address 408 and the topic end address 410. Conversely, when the subscribed information is within the transmitted topic start address 408 and topic end address 410, the selective call device 130 will continue to receive the transmitted information. Following the title start 408 and end 410 are full address, command and information data.

Referring to FIG. 5, the protocol of the second preferred embodiment illustrates a itemized topic catalog. The entry table is basically the same as the title address range method shown in FIG. 4, except as explained below. The header length 406 represents the distance from the number of the TOPIC address 502 to the TOPIC address entry table at the end of the entry TOPIC address ("TOPIC ADDR N") 512. The number of the topic address 502 informs the selective call device 130 of the total number of topic addresses included in the itemized tables of the addresses 504 and 512. The sub-entry address 504 and 512 identifies or corresponds to the full address, command and information data included in block 412.

Thus, when it is information application data transmission, the selective calling device checks the command number to determine whether to use the range method of the topic address or the itemization method. When it is a range method, the first (or starting) topic address is sent, followed by the last (or ending) topic address. If the address of the selective call device is within the range, i.e., the range of the start and end addresses, the remaining information is received to determine whether any of the addresses corresponds to the information service subscribed by the selective call device, otherwise, the selective call device saves the battery. On the other hand, when the itemized topic address method is adopted, a number including a topic address and each topic address of each information service is included, and when the topic address corresponds to information of the selective call device, a full address and subscribed information are searched. The itemized tables may be sent in ascending or descending order to allow the selective call device to quickly determine when its topic address is not in the itemized table to conserve battery.

Fig. 6 shows a block circuit diagram of a selective call device according to a preferred embodiment of the present invention. The selective call device (e.g., transceiver or receiver) 130 is powered by a battery 234 and operates to receive and transmit radio frequency signals via the antenna 202. The receiver 204 is coupled to the antenna 202 to receive radio frequency signals. A demodulator 206 is coupled to the receiver 204 to recover any information signals present in the radio frequency signal using conventional techniques. The recovered information signal from demodulator 206 is coupled to a controller 210, which decodes the recovered information in a manner well known to those skilled in the art.

In a preferred embodiment, the controller 210 comprises a microcomputer such as a microcomputer manufactured by Motorola, inc, for example 68HC11K4 or MC68HC11PH8, and has or includes a signal processor that performs the decoder functions typically performed in both hardware and software. The signal processor includes an address correlator 214 and a decoder 212 using methods and techniques well known to those skilled in the art. The address correlator 214 checks the information signal recovered from the output of the demodulator 206 for address information and correlates the recovered address information with one of a plurality of predetermined address information stored in the nonvolatile memory 220 of the selective call device. After the address correlator 214 determines that the received signal is directed to the selective call device 130, for example by correlating an address in the received signal with one of the predetermined addresses in the memory 220, the decoder 212 decodes the signal for the application identifier 402 to determine whether the message contains information service data. The absence of the application identifier 402 (fig. 4 and 5) indicates that the decoded message is a normal selective call message. Conversely, when the application identifier 402 is present and associated with the information service application identifier 402, the message includes the information service. The application identifier 402, command number 404, title address, and information address are preferably stored in the memory 222.

When the user of selective call device 130 has subscribed to at least one information service, memory 222 is programmed with the information service address and associated topic address (or sub-address) and associated topic address (or topic sub-address), such as by over-the-air techniques or other suitable programming method. The topic sub-address is associated with an information service. Thus, each information service has a unique topic address to allow selective call device 130 to determine when an information service is present within a particular transmission or message. The subject address may be a short form of information service sub-address or may be unique and distinct from the information sub-address while still identifying the presence of information service within a particular transmission.

Status information is also stored in memory 222, for example, memory 222 is a non-volatile memory or an electrically erasable memory, the status information indicating that the information is related to the information service that selective call device 130 is programmed to receive. After the decoder decodes the presented application identifier 402, the decoder decodes the command number 404, the topic address (or sub-address) and the information service address (or sub-address) and the information in block 412. When decoding a range method, for example, the command number is "000", the decoder further decodes the title start address 408 and the title end address 410 using the title length 406 to determine the start and end positions. If the topic address corresponding to the information service to which the selective call device subscribes is not within the range of the topic start address 408 and the topic end address 410, the decoder 212, through the support circuits 224, gates the user interface 216 causing the battery saver 218 to disconnect or remove power from the receiver 204.

On the other hand, when the partition method is decoded, for example, the command number is "001", the number of the partition address 502 is decoded, followed by the partition topic address 504 and 512. If the selective call device does not decode the address (or information service sub-address) corresponding to one of its information services, the battery saver 218 begins to remove power to the receiver 204.

Conversely, when the topic sub-address is found in the subentry address 504-512, the controller decodes the address, command and information data in block 412. Controller 210 retrieves address information for the selected information service sent to selective call device 130 and, when it is associated with the information service subaddress stored in memory 222, decoder 212 decodes the information service and stores the decoded information service in message memory 226.

Thus, after selective call device 130 checks that the received message is directed to the selective call device (if not, selective call device 130 conserves battery), selective call device 130 decodes the received message to determine whether it includes an information signal directed to selective call device 130. As discussed, the information data is identified by a unique address or sub-address different from the address of the selective call device to prevent the selective call device from searching the entire information data table before it can be determined that the received information does not contain the information service to which the selective call device is subscribed. As is well known, the service provider groups the latest data into different information services and transmits them, which information is received by any selective call device 130 that is authorized to receive information services 140 and 152. Selective call device 130 may quickly determine that its information service is not included in any particular transmission using a sub-address addressing scheme. When this determination is made, selective call device 130 conserves the battery, which would otherwise be drained quickly if selective call device 130 had to receive and search through the information data before it could determine that its information service is not present (or not found or not present).

After receiving, decoding and storing the selected information service in memory 226, selective call device 130 displays at least a portion of the stored message to the user, typically using display 228 such as, for example, a liquid crystal display. In addition, a prompt is given to the user via output signaler 232 while information is being received, decoded, and stored. The prompts may include audible prompts, visual prompts, vibratory or silent prompts, or combinations thereof, using known methods and techniques.

The support circuits 224 preferably include conventional signal multiplexing integrated circuits, voltage regulators and controls, current regulators and controls, audio power amplifier circuits, control interface circuits, and display lighting circuits. These elements are configured to provide support for the functions of the selective call device 130 as required by the user.

In addition, the controller 210 determines whether to save power when detecting the address information from the on or off state information in the memory 222. That is, when the received and restored address information is associated with a predetermined address in the non-volatile memory 220, the controller 210 checks the state information corresponding to the associated predetermined address information to determine whether to turn on the address. If the controller 210 determines that the associated predetermined address is not on, the decoder 212 is not invoked. In addition, the controller 210 commands the battery saver 218 to start saving power of the selective call device 130. The battery saver 218 signals the support circuitry 224 to enter a low power mode (battery saving mode). Many power consuming circuits may be manipulated into a low power or standby mode of operation. In addition, a signal from the battery saver 218 signals, or gates, the receiver circuitry 204 to a low power mode to save power.

Thus, when the associated address is not turned on, the selective call device 130 immediately conserves power without decoding the associated message and storing the message in the message memory 226, as indicated by the associated status information. Of course, after a while, the battery saver 218 will turn the receiver and other circuits back on. Methods of gating power savings in a selective call device are well known to those skilled in the art. In addition, the controller 210 refrains from any prompting of the user via the output signaler 232. Because the prompt is not performed again, the electric energy can be saved to the maximum extent. The status information corresponding to each predetermined address information stored in memory 222 allows controller 210 to disable functions in selective call device 130 and conserve power when the associated address is turned on, for example, when no information service is selected for the address port. Input control 230 is coupled to memory 222 and user interface 216 for receiving user inputs including, but not limited to, programming, manipulating data and sending commands to selective call device 130.

In addition to conserving battery power when the address of the selective call device 130 is not received, the selective call device 130 can conserve battery power when it determines that the information service or updates thereto do not include the particular information service to which the selective call device 130 is subscribed. Thus, the information services are identified by the information service address and the topic address (sub-address) transmitted with the information service, such that selective call device 130 determines when a transmission includes the desired information service. Due to the large number of available information service topics, the battery life will be destroyed if the selective call device is required to search for all information transmissions for its information topic. Thus, by checking the topic address and the information address, the selective call device can begin to conserve battery in addition to its ability to conserve battery when it does not receive the address of the selective call device.

Referring to fig. 7, a flow chart of the selective call device of fig. 6 is shown to illustrate the steps of receiving an information service. The selective call signal (or communication signal) includes an address identifying at least one selective call device for receiving the information service data. The selective call signal further includes an information service sub-address and a topic sub-address for identifying or relating to the plurality of information service data transmitted in the selective call signal, step 702. After receiving the selective call signal, the address correlator correlates the received address with the address stored in the memory 220 to determine whether the selective call signal (or communication signal) is directed to the selective call device 130, step 704. If the address received in step 704 is not associated with the address of the selective call device, the controller initiates a battery saving designated as the first battery saving routine, step 706. Instead, when the selective call signal is directed to the selective call device (the received address matches one of the predetermined addresses in memory), the controller searches the application identifier to determine the type of information being broadcast or transmitted, step 708. When the application identifier is not present, the message or information is decoded into a normal selective call message, step 710, in a manner well known in the art. On the other hand, when the application identifier is present in step 708, the selective call message or information is decoded into an information service, step 712, discussed in detail below. A command number is received and a determination is made whether the command number corresponds to a range method for topic address decoding, step 714. If so, the header length is decoded to determine the starting position and ending (offset) position of the title address, STEP 716. In the case of the range method, the header length identifies the location of the title start address and the title end address or title offset. From the topic start address and the topic end address, a range of topic addresses can be determined, STEP 718. Upon determining the range, the controller determines whether the topic address of any information (subscribed information or subscribed information service) subscribed to by the selective call device is within the topic address range included in the selective call signal being received, step 720. It will be appreciated that the command number may include a third option (not shown) that causes the selective call device 130 to omit saving the battery when, for example, the message is short or when airtime efficiency is more important than the battery life of the subscribing selective call device 130, as determined in step 714.

Returning to step 714, when the command number does not indicate a range method, but indicates a subentry method of the coded topic address in the selective call signal, the decoder decodes a header length identifying the starting position of the first and last subentry topic addresses in the decoded selective call signal, step 722. Thereafter, the decoder decodes the number of the itemized topic address included in the decoded selective call signal, step 724. It can be appreciated that the itemized topic address coding and decoding scheme is more suitable for small numbers of information topic addresses, while the range coding and decoding scheme is more suitable for transmissions involving large amounts of information traffic and topic addresses.

The itemized topic addresses 502- > 512 are searched by the selective call device and, when found, are associated with the topic address of the selective call device representing the information service (subscription information or subscription information service) to which the selective call device subscribes, step 726. From steps 720 and 726, if a topic address corresponding to the subscription information is not found, the controller initiates a second battery saving procedure, step 728. In this way, the selective call device can quickly conserve battery power without searching through the information service data to determine that the subscribed information is not within the selective call transmission signal.

In contrast, when the topic address is found, steps 720 and 726, the decoder searches for or decodes the information service subaddress corresponding to the topic address, step 730. When no information service subaddress is found or decoding of the information service subaddress fails, step 732, the controller initiates a third battery saving to enable the selective call device to save battery even when a subject address is found and no full information service subaddress is found, step 734. The topic address is preferably a shortened form of the information service sub-address, so that the topic address can be found when no corresponding information service sub-address (absent or not found) is present in the selective call signal. When the corresponding information service subaddress is found, step 732, the decoder receives, stores and presents the information service data, step 736.

In summary, in a selective call system, a method is provided comprising the steps of: the method includes encoding a selective call signal with an address assigned to a selective call device, a topic address, and an information service sub-address corresponding to subscription information of the selective call device, and broadcasting the selective call signal to a plurality of selective call devices of a subscription information service provider. In a selective call device, a method comprising the steps of: the method includes receiving a communication signal including an address and a topic sub-address indicating a subscription information service, initiating a first battery saving procedure when the address is not received, decoding the communication signal for the topic sub-address in response to receiving the address, and initiating a second battery saving procedure when the topic sub-address indicating that no subscription information is present is decoded. The method further comprises the steps of: decoding the communication signal for an information service subaddress representing a subscription information service in response to decoding the topic subaddress, and initiating a third battery saving procedure upon failure to decode the information service subaddress.

Claims (11)

1. A selective call device, comprising:

a receiver for receiving a selective call signal including a device address and at least one topic sub-address indicating subscription information therein;

an address correlator for correlating said device address in the selective call signal to determine whether the selective call signal is directed to the selective call device;

a decoder responsive to the address correlator for decoding the topic subaddress if the selective call signal is directed to the selective call device and the selective call signal has the topic subaddress; and

a battery saver coupled to the receiver for initiating battery saving when the selective call signal is not directed to the selective call device and for initiating battery saving when the selective call signal is directed to the selective call device but does not include the topic sub-address therein.

2. The selective call device according to claim 1, wherein said decoder decodes the selective call signal for an information service sub-address associated with the subscription information.

3. The selective call device according to claim 2, wherein said battery saver initiates battery saving when the information service sub-address is not present.

4. The selective call device according to claim 2, wherein said decoder decodes an information service subaddress of said subscription information in response to decoding the topic subaddress.

5. A method for battery conservation in a selective call device, comprising the steps of:

receiving a communication signal including a device address and at least one topic sub-address indicating a subscription information service;

determining whether said communication signal is directed to said selective call device based on said device address;

initiating a first battery saving procedure if said communication signal is not directed to said selective call device;

decoding said communication signal if said communication signal is directed to said selective call device; and

if the topic sub-address is not decoded to indicate that the subscribed information service does not exist, a second battery saving procedure is initiated.

6. The method of claim 5, wherein said decoding step further comprises the steps of:

decoding the communication signal for an information service subaddress indicating the subscription information service in response to decoding the topic subaddress; and

a third battery saving procedure is started when decoding of the information service subaddress fails.

7. The method of claim 5, wherein said decoding step further comprises: the communication signal is decoded for a command number representing a topic sub-address range.

8. The method of claim 7, wherein said second battery saving procedure is initiated if said topic sub-address is not within a range specified by a topic sub-address comprising a topic start sub-address and a topic sub-address offset therefrom.

9. The method of claim 7, wherein said second battery saving procedure is initiated if said topic sub-address is not within a specified range of topic sub-addresses comprising a topic start sub-address and a topic end sub-address.

10. The method of claim 5, wherein said decoding step further comprises the steps of:

the communication signal is decoded in order to indicate a command number of a method of encoding a topic sub-address of a partition table.

11. The method of claim 10, wherein said second battery saving procedure is initiated if said topic sub-address is not an entry of said itemized table topic sub-address.