Method and system for reducing message instances

The present invention relates to the field of wireless communication. More specifically, the present invention relates to messaging within a wireless transmission system.

Messaging is an evolving part of wireless transmission systems. However, the prior art has not been able to efficiently use insufficient radio resources for sending messages.

In the case of a typical broadcast, the message is sent at a particular time, on a particular channel, and with a particular channelization code. Broadcast messages are only retransmitted if there is a problem with delivery robustness or timing (ie, the device usually wants to receive the message at the right time and in the right place). ). However, broadcast messages are often sent across vast geographic areas and therefore contain a large number of cells. For this reason, broadcasting a message is only efficient when there are a large number of users receiving the message.

Multicast, in which a message is sent to a predetermined number of users, involves a limited number of recipients and selective transmission to each target recipient. In contrast to broadcast messages that are sent across vast geographic areas, multicast sends multiple instances of the same data (ie, messages) only to devices in the target group. Sending multiple instances of the same message, albeit more efficient than broadcasting, is not an efficient use of radio resources. That is, in the conventional multicast transmission, the message and the pointer associated with the message have a one-to-one correspondence, and as a result, the same message is transmitted a plurality of times.

Another approach is to assign group identifiers to multiple devices. Group identifiers reduce the one-to-one correspondence between messages and pointers, allowing a single instance of a message to be received by each device with that identifier assigned. However, this group identifier approach is only efficient if there is prior knowledge of the devices that form the group and the group identifier is expected to be used multiple times over a period of time. In addition, group identifiers must be set throughout the device via offline or online programming, which is not an efficient means of ad hoc (at least ad hoc for wireless networks) message delivery. That is, the group page from the source of the email may actually be an iterative group, but the RF network has no prior knowledge of that iterative group.

<p> Therefore, there is a need for methods and systems that allow a single message instance to be used for multiple recipients of the same message.</p>

<p> The present invention is a method and system for transmitting a message by reducing the number of message instances. A determination is made as to whether there are multiple WTRUs that identify the receipt of the same message. If you have more than one, you can send a single instance of the message to all incoming WTRUs.</p>

The present invention will be described with reference to the drawings. In all drawings, similar reference numerals represent similar elements. In the description of the present invention, the wireless transmitter / receiver (WTRU) can have transmission-only, reception-only, or transmission-and-reception functions. One example is a standard pager that can receive messages but not send them. In the present invention, reception capability is important for the reception of messages, in which case the particular device has at least wireless reception capability. On the other hand, WTRUs that can both send and receive can generally be used to receive one-way messages. Therefore, in the description of the present invention, the WTRU may be any device capable of receiving and / or transmitting data in a wireless environment.

Then, with reference to FIG. 1, a diagram illustrating a method of transmitting a multicast message according to the prior art is shown. In Figure 1, a unique destination identifier is used to identify multiple WTRUs 2, 4, and 5 as receiving the same message, namely message 1. The prior art provides a separate instance of message 1 for each WTRU (see WTRU2 and pointer 6, WTRU4 and pointer 8, and WTRU5 and pointer 9). Therefore, in FIG. 1, there is a one-to-one correspondence between the message and the pointer.

However, according to the present invention, the same message is sent to two or more destination identifiers (ie, to two or more WTRUs depending on whether the destination identifier is associated with one WTRU or multiple WTRUs). If so, the destination identifier is adjusted so that only one instance of the message is used.

The mobile network 11 is then shown with reference to FIG. The mobile network 11 includes a plurality of base stations 12, 13 that respond to the wireless network controller (RNC) 14 through one or more nodes B15. Multiple WTRU21 ~ 24 receive messages sent from the network. Base stations 12 and 13 transmit and receive signals via the antenna 27. WTRU21-24 have receivers or transceivers that receive signals from base stations 12 and 13 (via antenna 28 of WTRU21).

WTRU21-24 may be any of a plurality of devices supported by the system, such as mobile phones, pagers, Blackberry devices, or computers with modem connections. Base stations 12 and 13 are controlled by RNC14, which performs various network management and communication functions. Base stations 12 and 13 provide transmission functions and signals to be transmitted to WTRUs 21-24 within individual cells or transmission areas. In order to receive the signals transmitted from the base stations 12 and 13, the receiving function is provided by the RF stage of each WTRU. In the case of a two-way device, each WTRU has both transmit and receive functions, allowing WTRUs 21-24 to transmit uplink data and receive downlink data.

If the network detects a single message that identifies delivery to multiple WTRUs, such as WTRUs 21 and 22, the network refrains from sending multiple instances of the same message. Instead, WTRU21 and 22 are provided with message pointers that point to the same message. Each message pointer specifies a specific physical channel and time at which the message can be obtained.

The network evaluates the recipient list of a particular message to determine if there are multiple WTRUs that identify the receipt of a single message, thereby causing the reception of a single message to multiple WTRUs. Can be detected. A WTRU identified as the receipt of a single message can be tracked using the message address status. The message address status can be unique to a WTRU and indicates whether a particular WTRU belongs to a group of WTRUs that are identified for receiving the same message. If there are multiple WTRUs (21 and 22) that identify the receipt of the same message, a single instance of that message is sent to all of the received WTRUs. Other methods of determining and identifying WTRUs that identify the receipt of the same message and thus are candidates for reduced message instances are within the scope of the invention and can be practiced as described herein. Examples of such methods are given below.

FIG. 3 is a diagram of frames in chronological order with a timing sequence 40 showing a message sent to multiple destination identifiers 42, 44, and 46, i.e., a single instance of message M. Destination identifiers 42, 44, and 46 can be associated with one or more WTRUs, respectively. In this case, the message "M" has been identified to be delivered to the WTRU associated with destination identifiers 42, 44, and 46. That is, instead of providing multiple instances of message M, it provides a single instance, thereby maximizing system resources.

When implementing this technique, there is a general restriction that the message must be delivered in such a way that all WTRUs that receive the message can receive the message while it is being sent. As an example, the message must be sent with a time delay sufficient for all WTRUs to be prepared to receive the message after the time of sending the last destination identifier.

It is important to note that the use of pointers to specific messages may occur with any number of destination identifiers, and that there may be messages destined for other WTRUs in between, if desired. Further, as mentioned above, one or more of the destination identifiers may actually be some WTRU group identifiers in a manner well known to those skilled in the art of wireless technology.

The determination of when the same message can be used multiple times according to the present invention can be refined and adapted as necessary. That is, the determination can be carried out in various embodiments.

As an example, in the first embodiment, the source of a message can be programmed to associate multiple incoming WTRUs with the same message. Using an email message with multiple recipients as an example, when such a message is received, the wireless network compares the recipient list against the coverage it has for those recipients. Due to different locations or network alliances, it may be necessary to separate the message and recipient into separate transmissions. However, the solution of the present invention can be utilized if it is possible for two or more of the received WTRUs to receive transmissions of the same identification, followed by transmissions of the same message.

In the second embodiment, the message and the data about the received WTRU enter the wireless network separately, and many types of messages can tolerate some delivery delay without harm. In this case, the system compares the messages for duplicates over a fraction of this acceptable delay time. This can often be done with minimal computation using techniques such as hash functions. If duplicates are detected, a check is made to determine if any of the duplicate messages can be sent in a single transmission. If it can be sent, a pointer to a single instance of the duplicate message is provided to the WTRU where the receipt of the duplicate message is identified.

In a third embodiment, the wireless system can include an entity that monitors transmissions to the WTRU. This entity sets the likelihood factor as to whether a particular WTRU group receives the same message transmission. When a message to one of those WTRUs is received, it triggers a delay and a search for duplicate messages on the other device before sending that message. If duplicates are detected, a single instance of the message is sent. If not found, a separate instance of the message is sent to each incoming WTRU.

In a fourth embodiment, the wireless system is pre-programmed to monitor a group of specific device identifiers and checks for duplicate messages for individual identifiers in that group. If duplicates are detected, a single instance of the message is sent. If not detected, a separate instance of the message is sent to each incoming WTRU.

To implement the present invention in a 3GPP cellular network, broadcast the destination identifier and pointer identified in Figure 3 over the Broadcast Common Control Channel (BCCH) or its equivalent logical control channel to the entire cell. Inform the user. A BCCH or equivalent logical control channel is associated with a broadcast transport channel (BCH) or equivalent broadcast transport channel applied to the primary common control physical channel (PCCPCH). Alternatively, the BCCH or equivalent logical control channel can be associated with the forward access channel (FACH) applied to the secondary common control physical channel (SCCPCH).

In Figure 3, the WTRU must examine the entire timing sequence 40 to determine if there is a message for itself. For more efficient processing and reduced WTRU battery consumption, it is necessary to provide deterministic scheduling of destination identifiers and pointers. Furthermore, since the need to obtain information and signaling periodicity is unique to the signaling information being signaled, it is necessary to signal logically separate information (ie, destination identifiers and pointers) independently. Therefore, in another embodiment of the invention, the destination identifier and pointer are held in a unique system information block (SIB). Therefore, in this embodiment, the destination identifier and pointer are associated with a particular SIB, thereby allowing the WTRU to simply determine the individual SIB to read in order to receive the message. That is, the list of destination identifiers and pointers can be relatively large. The SIB information can be split into multiple independent transmissions to avoid having the WTRU look up each destination identifier and pointer contained in the timing sequence (such as timing sequence 40). Alternatively, it is possible to divide different classifications of destination identifiers and pointers into multiple SIBs.

The WTRU can determine which SIB should be read from the Master Information Block (MIB) that identifies the scheduling of individual SIBs. That is, in this embodiment, instead of the WTRU looking at all destination identifiers and pointers contained in a particular timing sequence (such as timing sequence 40), the WTRU simply looks at the MIB and is applicable (included in the SIB). The destination identifier and pointer to be used can be determined quickly. Therefore, destination identifiers and pointers are associated with a particular SIB. Therefore, the user only needs to obtain the SIB associated with the service.

FIG. 4 is referenced to illustrate this embodiment. FIG. 4 shows a MIB 502 containing pointers 504, 506, and 508. Note that the MIB may be unique to each cell. Therefore, the WTRU reads the MIB each time it enters a cell. Reading MIB502 tells WTRU where to find your SIB. The SIB informs the WTRU of the destination identifier of the WTRU and the time interval at which the pointer is presented. Also note that the destination identifier and pointer may be updated periodically. For example, in the case of stock prices, a new message may be sent every 10 minutes. In that case, the WTRU reads the SIB every 10 minutes and receives the updated information, but does not need to read the MIB. This is because the MIB does not change unless the actual scheduling of destination identifiers and pointers changes.

For example, continuing to refer to FIG. 4, the MIB 502 includes pointers 504, 506, and 508 that point to SIB1, SIB2, and SIB N, respectively. The WTRU subscribed to Service A reads the MIB and is guided to SIB1 510. From reading SIB1 510, WTRU reads service A's destination identifier and pointer 512. The WTRU can then retrieve the message about service A. In this embodiment, any number of WTRUs can be associated with the destination identifier of service A (ie, all users subscribed to service A). Therefore, all WTRUs that subscribe to Service A are directed to a single instance of any message sent as part of Service A by reading the MIB and SIB. The WTRUs associated with services B and X can likewise be directed to a single instance of the message sent according to those services.

The embodiment described above and shown in FIG. 4 can be modified so that the actual message is included in the SIB as shown in FIG. In Figure 5, the WTRU reads the MIB as above, but here the extra step is eliminated because the WTRU gets the actual message when it gets its own SIB. This also allows a single instance of a message to be sent to multiple WTRUs. That is, each WTRU reads MIB601 and is directed to SIB1 604, which contains a single instance of message 602 that is currently being sent for service A.

Note that it is possible to provide multiple levels of pointers and messages. Thus, comprehensive message pointers can be included, such as pointers to messages that indicate the availability of more unique types of messages. The user can then choose to receive a particular type of message, either by presetting or by selecting when receiving a comprehensive message. This choice can be made to inform the network that the WTRU will receive the message, or the choice can be passive so that the WTRU can respond to more specific messages. As an example, a user entering a commercial space can be provided with commercial information so that the user can choose to receive the commercial information.

FIG. 6 is a flow chart illustrating method steps performed by a message arrival analysis routine according to a preferred embodiment of the present invention. When a message arrives, it is determined whether it duplicates a message in the pending recipient list (step 305).

If the decision in step 305 gives a positive result, the WTRU is added to the recipient list for that message (step 310). At step 315, it is determined whether the maximum retention time for the instance is less than the time currently set in the recipient list. If it is short, adjust its retention time to an appropriate value (step 320).

If the decision in step 305 yields a negative result, the message is delayed to determine if other recipients can be found (step 325). If the message cannot be delayed to find other recipients, determine if the message will be sent to more than one recipient (step 330). If the message is not sent to more than one recipient, the message is scheduled for normal delivery (step 335). If the message is sent to more than one recipient, or if it is determined that the message can be delayed to find another recipient, an entry is created in the recipient list queue and one or more. Multiple WTRUs are added and the retention time is set to an appropriate value (step 340).

FIG. 7 is a flow chart illustrating method steps for periodically checking for a list of recipients in the multicast queue beyond a predetermined retention time, according to a preferred embodiment of the present invention. If it is determined that there is a list of recipients remaining in the multicast queue beyond the retention time (step 405), the WTRUs in that list of recipients are divided into groups within the same data delivery coverage area (step 410). .. Then determine if there is another group to send (step 415). If there is another group to send, schedule the WTRU identifier, message pointer, and one message instance to be sent (step 420). If there is no other group to send, delete the recipient list (step 425).

Although the present invention has been described in terms of preferred embodiments, other modifications within the scope of the invention outlined in the claims mentioned above will be apparent to those skilled in the art.

<figref num="1">FIG. 5 is a diagram of a framed time sequence having a one-to-one correspondence between a message and a pointer for multiple WTRUs to receive the same message according to the prior art.</figref><figref num="2">FIG. 5 is a diagram of a mobile network according to the present invention in which a plurality of WTRUs receive messages.</figref><figref num="3">FIG. 5 is a diagram of a framed time sequence according to the present invention in which only a single instance of a message is transmitted even though the message is identified as being delivered to multiple destination identifiers.</figref><figref num="4">It is a figure which processes a destination identifier and a pointer included in a framed time sequence more efficiently.</figref><figref num="5">It is a modification of the figure shown in FIG. 4 in which the message is directly contained in the SIB.</figref><figref num="6">FIG. 5 is a flow chart illustrating method steps performed by a message arrival analysis routine according to a preferred embodiment of the present invention.</figref><figref num="7">It is a flowchart which shows the method step which periodically checks whether there is a receiver list in a multicast queue beyond a predetermined holding time according to a preferable embodiment of this invention.</figref>

Code description

11 Mobile Network 15 Node B1514 Wireless Network Controller (RNC) 12, 13 Base Station