This disclosure relates generally to Cell Broadcast Service and its applicability to Machine-to-Machine communications.
At present, there is no provision for “Group based addressing” for machine-to-machine (M2M) devices in 3GPP standards. As a result, there is no general mechanism that allows for a broadcast to be addressed to a defined group of devices for M2M application purposes. Although a Cell Broadcast Service (CBS), as disclosed in TS 23.041 exists, is not oriented towards M2M purposes and does not address many of the needs for M2M communications.
In general the existing CBS is used to display broadcast Text information for human end user consumption via the MMI. Because it is intended for interactions with human end users, CBS does not consider issues relevant to M2M needs, including the effect of these services on battery consumption. Existing CBS implementations increase battery consumption as the broadcast intervals are geared towards human end users and to mobile users that may be traveling quickly through a cell. The existing CBS implementations do not consider the behavior requirements of M2M that may be stationary (e.g. smart utility meters that rarely communicate and when they do may not be doing so in a time sensitive manner). Such M2M systems often have different battery concerns as they be deployed in hostile environments requiring extended battery support.
Current solutions do not define a standardized method to define a M2M group. Operators in 3GPP M2M related activities have expressed the need for such a mechanism for the 3GPP system but none is yet defined. Stage 1 Service requirements in the area have been documented in ongoing SA1 Technical Spec TS 22.368 standardization activities related to M2M communications. Group Based Addressing MTC (Machine Type Communication) Feature in TS 22.368 v1.1.1 states: “ . . . For the Group Based Addressing MTC Feature: It shall be possible to send a broadcast message to a large group of MTC Devices affiliated with a single MTC Subscriber.” but no indication of how this is to be performed is provided.
Stage 2 publications for the group based addressing 3GPP TR 23.888 has not identified a solution. Nor have they identified the method by which the Cell Broadcast Service could be exploited to solve the “Group addressing” feature.
Those skilled in the art will appreciate that related information can be found in the following publicly available standards related documents, each of which is expressly incorporated by reference herein:
Therefore, it would be desirable to provide a system and method that obviate or mitigate the above described problems
It is an object of the present invention to obviate or mitigate at least one disadvantage of the prior art.
In a first aspect of the present invention, there is provided a method of sending a message to a plurality of Machine-to-Machine devices connected to a radio access network. The method comprises the steps of identifying a group of devices that the message should be sent to; indicating the identified group in a cell broadcast service message; and transmitting the cell broadcast service message to the indicated group.
In an embodiment of the first aspect of the present invention, the step of indicating includes encoding the identified group in the cell broadcast message. Optionally, the identified group is encoded in the cell broadcast message by storing a group identifier in a “Message Identifier” field of the message. In another embodiment, the method further includes the step of including schedule information in the cell broadcast service message before the step of transmitting the message. Optionally, the schedule information identifies an anticipated next cell broadcast service message delivery window. In a further embodiment, the step of transmitting includes broadcasting the message to all nodes connected to the radio access network.
In a second aspect of the present invention, there is provided a method of processing a cell broadcast service message in a terminal device. The method comprises receiving the cell broadcast service message over a radio access network interface, the message identifying a group; and processing the received cell broadcast service message if the group identified in the message corresponds to a group associated with the terminal device.
In an embodiment of the second embodiment, the step of receiving includes receiving the cell broadcast service message; and checking the received message for an encoded group identifier. Optionally, the step of checking includes checking a “Message Identifier” field in the received message. In another embodiment, the step of processing includes determining that the group identified in the received message does not correspond to a group associated with the terminal device and ignoring the message. In another embodiment, the step of processing includes retrieving a list of groups associated with the terminal device from a memory preconfigured to identify the groups associated with the terminal device. Optionally, the method further includes the step of comparing the group identified in the message with the groups in the retrieved list. In a further embodiment, the step of processing includes determining if the received message includes scheduling information. Optionally, the step of performing standard processing on the received message upon determination that the received message does not include scheduling information. This embodiment can also further include the step of determining a next anticipated cell broadcast service message window in accordance with scheduling information included in the received message, and optionally the step of ignoring all incoming cell broadcast service messages until the determined next window.
In the third aspect of the present invention, there is provided a node for transmission of cell broadcast service messages through a radio access network. The node comprises a memory, a network interface and a processor. The memory stores group identifiers. The network interface transmits messages through a radio access network. The processor composes a cell broadcast message in accordance with received cell broadcast service message content, retrieves a group identifier to allow addressing the cell broadcast service message to a group associated with the identifier, and transmits the cell broadcast service message to the group through the network interface.
In an embodiment of the third aspect, the processor addresses the cell broadcast service message to the group by encoding the group identifier in the cell broadcast message. Optionally, the processor encodes the group identifier in a “Message Identifier” field. In another embodiment there is further included a scheduler for determining the next anticipated cell broadcast service message delivery window associated with the group associated with the identifier and for providing scheduling information associated with the determined window to the processor for inclusion in the cell broadcast service message.
In a fourth aspect of the present invention, there is provided a node for processing a cell broadcast service message. The node comprises a network interface, a memory and a processor. The network interface receives the cell broadcast service message. The memory stores a preconfigured group identifier associated with the node. The processor determines that the received message is addressed to a group, and processes the message upon determining that the addressed group corresponds to the preconfigured group identifier.
In an embodiment of the fourth aspect of the present invention, the memory is embedded on a subscriber identity module. In another embodiment, the processor determines the received message is addressed to a group by inspecting a “Message Identifier” field in the received message. In a further embodiment, the node further includes a scheduler for obtaining from the processor a next anticipated cell broadcast service message delivery window upon processing of the message, the scheduler operatively connected to the network interface to instruct the network interface when to next anticipate delivery of a cell broadcast service message in accordance with the delivery window.
Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.
Embodiments of the present invention may be described, by way of example only, with reference to the Figures wherein:
The present invention is directed to a system and method for a machine-to-machine group based addressing system using cell broadcast services.
Reference may be made below to specific elements, numbered in accordance with the attached figures. The discussion below should be taken to be exemplary in nature, and not as limiting of the scope of the present invention. The scope of the present invention is defined in the claims, and should not be considered as limited by the implementation details described below, which as one skilled in the art will appreciate, can be modified by replacing elements with equivalent functional elements.
In embodiments of the present invention, solutions to some of the deficiencies in the prior art are provided by extending the Cell Broadcast Service as a transparent bearer for M2M type broadcast communication as opposed to just a messaging service for Human end user consumption. Some of the extensions provided in embodiments discussed below may include:
The MTC Feature Group Based Addressing supported in the existing art is intended for use with a large group of MTC Devices belonging to the same MTC Subscriber, for which the network operator wants to optimize the message volume when many MTC devices need to receive the same message. In one embodiment of the present invention, the 3GPP system provides a transparent message channel towards the M2M devices and should not be concerned with the content or nature of the broadcast message. By making such a service available, a number of different functions can be enabled. A non-exhaustive list of such uses includes:
The Cell Broadcast Service (TS 23.041) provides a basis for defining a transparent bearer for M2M by re-using the cell broadcast as a means to efficiently address a group of M2M devices. The Cell Broadcast Service can be characterized by the following aspects:
Embodiments of the present invention allow the MTC server to act as a Cell Broadcast Entity (CBE) which can connect to the Cell Broadcast Center through which the MTC server can initiate broadcast of CBS messages to a group of devices. The basic existing coding of an embodiment of a CBS message of the present invention contains the following:
It should be noted that TS 23.041 shows flexibility in defining and usage of new “Message IDs”. This is done so that some ranges are reserved for future standardization, while other ranges are set aside as PLMN operator specific ranges (i.e. A000-AFFF, B000-EFFF).
The basic behaviour of the system of the present invention is that the M2M ME attempts to receive the CBS messages for which Message Identifiers are in the “search list” of the SIM/USIM. For example, using PLMN operator specific range Message IDs allows one to potentially to map “Group IDs” to Message IDs “ . . . As an example, Group ID 0 can be defined as Message ID A000, while Group ID 1 can be defined as Message ID A001, etc.
In such a configuration, an M2M device can be assigned to Groups and would be programmed with the Message IDs associated to the Groups IDs it belongs. This configuration could be stored on the subscriber identity module (SIM) or equivalent element. This approach permits UEs to belong to multiple groups by listening for multiple Message IDs. The existing “Content of Message” parameter can carry the M2M “application message” that MTC Server intends to broadcast to the Group (via CBC). The Data Coding scheme permits a text and binary encoding.
When communicating with the CBC the repetition period and the number of broadcasts are indicated by the CBE. In the context of M2M the information may not be as dynamic as for other applications (e.g. text based dynamic traffic reports or advertisements aimed toward human end users). As well for M2M devices that are stationary (e.g. utility meters) the repetition rate can be low as compared to attempting to broadcast messages to mobile devices traveling at high velocity through the cell. CBS offers flexibility for up to 15 pages to be concatenated to form a CBS message.
As opposed to a typical text based CBS message that is presented to human user via the user equipment interface, the present invention allows the M2M UE devices to have the ability to inform a higher level M2M application layer of received M2M messages for suitable processing. Extensions that are envisioned that would benefit M2M broadcast services can include
Among many advantages that can be provided by different embodiments of the present invention, existing base functionality with (using a Group ID to message ID mapping) allows for implementation without impacting a large number of standards changes for M2M device support. Additionally, CBS enables broadcasts to a large UE population in an efficient manner Current CBS message definition permits its usage as a bearer for M2M Group messages. Message Id can serve as, or be mapped to, a M2M application level “Group ID”. This can be expanded by introducing an explicit “group Id” in the message definitions. Flexibility between CBE and CBC allows for broadcasts that permit the MTC server to define geographic areas over which messages are to be broadcast as well as for the scheduling of the message. Flexible message length through use of concatenated CBS messages can be supported. The CBS can schedule message for broadcast in CBS DRX mode for mobile stations. A Schedule message is helpful in minimizing battery usage for Cell Broadcast in the Mobile Station, because it allows the MS to ignore transmissions of CBS messages the customer is not interested in.
3GPP TS 25.324 describes a standard Broadcast/Multicast Control. It contains definition of 2 key messages BMC CBS message, BMC Schedule Message. Based on the definition of BMC CBS Message the following new “BMC CBS M2M Message” can be defined which introduces a “M2M Group ID”. The CBS Message can carry the cell broadcast data and the address information if the address information is based on GSM CBS.
One skilled in the art will appreciate that a group id definition can allow for globally unique identifiers. For example a group id can be prefixed/built/constructed with unique mobile country codes and mobile network codes as per existing IMSI definition (e.g. MCC+MNC+group ID).
The creation of new “M2M CBS message” may also require a new Message Type value.
In each CBS schedule period, a BMC Schedule Message specifies both the time slot locations for each CBS message, and the time at which the next Schedule Message (for the next CBS schedule period) will be sent. To inform devices in a specific M2M group of succeeding CBS M2M messages, an optimization of the standard method provides the ability to indicate when a CBS M2M Message is to be broadcast. In one embodiment, this is achieved by updating the “message description” to be able to carry the M2M Group ID. This preferably indicates whether the associated Message ID is associated to a CBS M2M message (or regular CBS message) as well as indicating to which specific M2M Group ID the message is applicable.
M2M devices preferably maintain a search list of Group IDs representing the Group(s) to which they belong. The Group IDs can be provisioned in the device in a number ways including: Over the Air Activation and/or assigned as part of “PCO” (Protocol Capability Options“) when first attaching to the 3 GPP system, as well as other standard mechanisms that will be understood by someone skilled in the art.
An M2M device can report a received CBS M2M message to a higher level M2M application level upon reception of a message addressed to the Group ID to which the mobiles belong (i.e. In mobile Group ID search list).
A system and method of the present invention provide for a number of different advantages that will be apparent to those skilled in the art. Advantages that may be provided by some embodiments (not all embodiments of the present invention will provide all or even any of the following advantages) include:
As discussed above, a mechanism can be provided to encode a group identifier into a standard CBS message, and then broadcast the message. Properly configured user equipment will then be able to identify which messages are relevant by only listening to the messages associated with their groups. In an M2M environment it may be important for terminal devices to enter power saving states instead of constantly listening for broadcast messages. To facilitate this, the M2M CBS messages can include scheduling information that will provide the terminal device with an indication of a time window in which the next message will be received. This will allow the device to remain in a power saving state between possible windows.
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Embodiments of the invention may be represented as a software product stored in a machine-readable medium (also referred to as a computer-readable medium, a processor-readable medium, or a computer usable medium having a computer readable program code embodied therein). The machine-readable medium may be any suitable tangible medium including a magnetic, optical, or electrical storage medium including a diskette, compact disk read only memory (CD-ROM), digital versatile disc read only memory (DVD-ROM) memory device (volatile or non-volatile), or similar storage mechanism. The machine-readable medium may contain various sets of instructions, code sequences, configuration information, or other data, which, when executed, cause a processor to perform steps in a method according to an embodiment of the invention. Those of ordinary skill in the art will appreciate that other instructions and operations necessary to implement the described invention may also be stored on the machine-readable medium. Software running from the machine-readable medium may interface with circuitry to perform the described tasks.
The above-described embodiments of the present invention are intended to be examples only. Alterations, modifications and variations may be effected to the particular embodiments by those of skill in the art without departing from the scope of the invention, which is defined solely by the claims appended hereto.
This application claims the benefit of priority to U.S. Provisional Patent Application No. 61/304,707 entitled “M2M GROUP BASED ADDRESSING USING CELL BROADCAST SERVICE” filed on Feb. 15, 2010, the entirety of which is enclosed herein by reference.
Number | Date | Country | |
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61304707 | Feb 2010 | US |