KR20070022882A - Method for distinguishing different types of data content in data packets in a wireless communication system - Google Patents

Abstract

An apparatus and method for reducing latency in push-to-talk (PTT) communication of a wireless communication network is disclosed. Time sensitive push-to-talk (PTT) related messages are identified in a specially designed header and can be handled differently by wireless mobile devices. These messages with specially designed headers are transmitted from the wireless transmission unit to the mobile device via signaling channels, as opposed to being transmitted as dedicated channel traffic.

PTT communication, latency, mobile device, signaling channel, data packet, header.

Description

FIELD OF DISTRIBUTION DIFFERENT TYPES OF DATA CONTENT IN DATA PACKETS IN A WIRELESS COMMUNICATION SYSTEM}

Cross-Reference of Related Applications

The present invention discloses US Provisional Serial No. 60 / 581,790, filed June 21, 2004; Priority is claimed on US Provisional Serial No. 60 / 686,131, filed May 31, 2005. The contents of these documents are incorporated herein by reference.

Background

1. Field of the Invention

The present invention relates to data transmission in a wireless communication system, and more particularly, to identifying data types transmitted in data packets of a wireless communication system.

2. Description of related technology

In wireless communication systems, push-to-talk (PTT) features are becoming popular in the service sectors. PTT provides "dispatch" voice services that operate over standard commercial wireless infrastructures such as code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), and Global System for Mobile Communications (GSM). Support. In the dispatch model, communication between end points (end user devices) occurs within virtual groups, and the voice of one "caller" is broadcast to one or more "listeners." A single instance of this type of communication is called a dispatch call, or simply a PPT call. PPT calls are specific examples of groups that define the characteristics of a call. In essence, a group is defined by a membership list and associated information, such as a group name or group identification. In the absence of a wireless multicast channel, each group is formed by a combination of individual point-to-point connections between the application servers managing the call and each end point. In addition, each endpoint is known as a client.

1 illustrates a prior art architecture 100 that supports PTT communications. The architecture includes the deployment of a single application server area coupled with the carrier's CDMA infrastructure and packet data network. Each area of the application servers is located through a particular portion of the carrier packet data network. The application server in the area may be routing traffic between one or more packet data service nodes (PDSNs) of the carrier network. A communication device 102 that supports the PTT feature is in communication with a base station 104. The base station 104 is in communication with the high speed network 106 and the PTT communications received from the communication device 102 are sent to the packet data service node (PDSN) via the base station 104 and the network 106. The PDSN communicates with the high speed network 106 and the network 108 of the application server connected with the PTT network 110. The PDSN forwards PTT communications to the application server 112 of the PTT network 110.

Application server 112 receives the PTT communication from one member and sends it to all members of the PTT group. In general, the PTT communication is received as data packets from the network 110, and the PTT communication sent by the application server 112 also exists in the data packet format. The receiving mobile switching center (MSC) and the connected base station (BS) then establish a dedicated channel for transmitting PTT communication to the receiving mobile client (PTT member).

2 shows a prior art message flow 200 for PTT call setup. When a PTT user (sender) is ready for PTT communication, a PTT request is made when the user presses a PTT enable button on the user's mobile device 102. In response to the PTT request received by the mobile device 102, the mobile device sends a call request message to the application server 112, also known as a PTT execution dispatcher. Application server 112 receives and processes the call request message. Call request processing includes identifying a PTT user, identifying a PTT group to which the PTT user belongs, identifying a member of the PTT group, and preparing announce call messages sent to each member of the PTT group. Steps.

After the application server 112 sends announce call messages, each announce call message is received by the MSC and forwarded to the BS by the MSC. BS broadcasts an announce call message. If the mobile client that is the target recipient is valid, the mobile client sends an accept call message back to the application server 112. After receiving an accept call message from one or more mobile clients, application server 112 sends a floor grant message back to the originating mobile client. There may be one or more target users in the sender's PPT communication group, and if one or more target mobile clients are valid, the application server 112 will grant the floor to the sender. After receiving the floor grant message, the PTT requesting mobile client (sender) may make a PTT communication. The PTT related messages described above are sent as data packets, preferably Internet Protocol (IP) data packets. In addition, other data formats may be used to carry these PTT related messages.

The PTT communication setup process described above is time sensitive so that the initial PTT latency shown in FIG. 2 is affected by network traffic. Long latency directly affects users of PTT communication. Therefore, it is desirable to have a system and method for reducing PTT latency, so the present invention prioritizes such a system and method.

Summary of the invention

The apparatus and method of the present invention can quickly respond to PTT related inputs from a PTT communication user. In one embodiment, a method is provided for reducing latency in push-to-talk (PTT) communication between a plurality of mobile devices, each mobile device communicating with a wireless communication network via signaling channels and data channels. do. The method comprises receiving a data packet from a data communication network comprising a PTT message and having a header at a wireless signal transmission point; Examining the header of the data packet; If the header of the data packet has a predetermined value, sending a PTT message to the mobile device over the signaling channel as opposed to waiting for a dedicated access channel to be connected.

In another embodiment, an apparatus is provided for reducing latency in push-to-talk (PTT) communication between a plurality of mobile devices, each mobile device communicating with a wireless communication network via signaling channels and data channels. do. The apparatus includes a network interface unit for receiving data packets from a data network, each having a header and including a PTT related message, a storage unit for storing a data packet with a header, a controller unit for analyzing a header of the stored data packet, and a stored data packet. And a radio interface unit for transmitting to the mobile device via a radio signal, and when the header of the stored data packet has a predetermined value, transmit the stored data packet to the mobile device through a signaling channel.

Accordingly, the present apparatus and methods have the advantage of reducing latency in PTT communication between a plurality of users through the use of continuously established signaling channels, as opposed to periodically established dedicated communication channels. Other advantages and features of the present invention will become apparent after a review of the following brief description, the detailed description, and the claims.

Brief description of the drawings

1 is a prior art structure of a wireless communication network.

2 is a prior art message flow for setting up a PTT call.

3 is an exemplary embodiment of a header of a data packet.

4 is an exemplary embodiment of a service field type of a header of a data packet.

5 is a flowchart of an exemplary embodiment of a base station process.

Detailed description of the invention

In the description, the terms "communication device", "wireless device", "wireless communication device", "PTT communication device", "portable device", "mobile device", and "handset" may be used interchangeably. The term "application" as used in the description will include executable and non-executable software files, raw data, aggregate data, patches, and other code segments. The term "exemplary" means that the elements or embodiments disclosed are by way of example only and do not represent any preference of the user. Moreover, unless otherwise specified in the description, the same numbers used throughout the various figures refer to the same components.

In general, the systems and methods of the present invention reduce latency delays for push-to-talk (PTT) communications between a wireless device and a wireless communications network. Typically, when the wireless device is ready to send PTT communication to the base station (BS), the wireless device sends a channel request to the BS over a signaling channel. After the BS establishes a reverse access channel, the wireless device will send PTT communication to the BS over this reverse access channel. Similarly, when the BS is ready to send PTT communication to the wireless device, the BS broadcasts a paging message on the signaling channel. After the wireless device approves the paging message, the BS establishes a forward access channel with the wireless device and sends PTT communication to the wireless device over the forward access channel. PTT communications as well as channel request and other PTT call setup messages as shown in FIG. 2 are transmitted as data packets over a wireless communications network and a data communications network.

However, PTT communication is not the only service provided to users of a wireless device, and other services such as electronic mail, Internet web browsing, short message services (SMS), and the like may also be available to users. Application server 112 handles PTT communications between members of PTT groups as well as other services provided to wireless devices. In addition, data associated with all these services is transmitted as data packets between the application server 112 and the wireless devices 102. In addition, these data packets are processed by the base station 104 and the application server 102 like any other data packets. Additional data packets increase traffic and slow down the wireless communication network.

Because data packets of a wireless communication network support different types of services, they contain data about different types of services and can be identified by the header of the data packets. According to one embodiment of the invention, data packets can be broadly classified into three categories according to their content: PTT call setup related messages, PTT communication messages, and other service related messages. Most messages related to PTT call setup are time sensitive because they can be perceived by the PTT user. Also, PTT communication messages are time sensitive because delays can cause jitters in PTT communication. Other general services related messages include voice communications, e-mail messages, web browsing messages, and short message services. These non-PTT related messages are less time sensitive. The above-mentioned services are merely exemplary services, and those skilled in the art understand that services not listed above may also be classified in terms of time sensitive.

3 shows a packet header 300 according to one embodiment of the invention. There are a plurality of fields, each labeled with a specific function. An 8-bit field, Service Type (TOS) 302, indicates a service type for data in data field 304. 4 shows one embodiment of an 8-bit TOS field (400), where the 8-bit TOS field 302 is classified into two subfields: class selector 402 and service selector 404. Class selector 402 may be used to identify a class that belongs to data 304. For example, the data may be a PTT setup message, and thus may belong to a time sensitive class selector; Alternatively, the data may be part of a PTT communication and thus belong to a less time sensitive class compared to the PTT setup message. The service selector 404 can be used to identify the service belonging to the data 304. For example, the data may be a PTT call accept message. Those skilled in the art understand that they may devise or use different fields of the data packet header indicating the same information.

Data packets may be generated by the wireless device when communicating with the application server 112. The wireless device generates a data packet for the particular service being handled and sets the TOS field to reflect the service. The wireless device examines the TOS field and determines whether to request a dedicated channel to send data packets to the base station 104. Alternatively, the wireless device may already know about the type of data it is dealing with and may use the information to determine whether to send a data file to the base station 104 via the signaling channel. After receiving the information, the base station 104 forwards the data packet to the application server 112 for processing.

Application server 112 may also generate data packets and set the TOS field of the message according to the type of data related service. For example, the application server 112 may receive a call accept message of the data packet from the wireless device and then generate a floor grant message to be sent to the PTT originating user. The floor grant message is sent to the base station 104 serving the PTT originating user in a data packet. Base station 104 receives a data packet and examines its TOS field. The base station 104 determines that this is a time sensitive message and then sends a floor grant message to the wireless device of the PTT originating user via the signaling channel. If the data packet contains website related data that is not a time sensitive message, the base station 104 requests a dedicated channel to be established between the base station and the wireless device. After that, the data related to the website is sent through a dedicated channel.

5 is a flow diagram 500 for a process for handling incoming data packets at a base station 104. When base station 104 receives a data packet (step 502), it examines the header of the data packet (step 504). If the TOS field in the packet header is marked as time sensitive, base station 104 transmits the information of the data packet on the signaling channel (step 506). If the TOS field of the header of the packets is not marked as time sensitive, the base station 104 will establish a dedicated channel (step 508) and send the data packet over the dedicated channel to the target wireless device (step 510).

The following is a usage scenario illustrating the present invention. When the first user accesses e-mails through his wireless device, the user can send a reply mail to the second user. The wireless device packs the reply mail of the data packet and marks the TOS field of the data packet as a non-time-sensitive electronic mail service. The wireless device then requests a reverse channel and sends a data packet to the base station 104 over this reverse channel. Base station 104 receives the data packet and, according to the header of the data packet, forwards the data packet to its destination, application server 112.

The application server 112 receives the data packet and finds that it is a reply email for the second user. The application server 112 then forwards the data packet to the base station 104 serving the second user. Base station 104 receives a data packet, examines its TOS field, and requests a dedicated access channel. After the forward access channel is established, the base station 104 sends a data packet to the wireless device of the second user over the forward access channel.

After the second user reads the reply email, he decides to communicate with the first user via a push-to-talk feature. The second user activates a PTT button on his wireless device and the wireless device generates a data packet with a call request message to the application server 112. The wireless device sends the data packet with the call request message to the base station 104 over the signaling channel because the wireless device sees the data packet as containing a time sensitive message. Base station 104 receives the data packet and forwards it to application server 112.

Application server 112 examines the data packet and sees if it contains a call request message. The application server 112 then checks whether the PTT communication group to which the first and second users belong is used. If another user has a floor for the PTT communication group, the call request will be rejected. If the floor of the PTT communication group is valid, the application server 112 identifies the members of the PTT communication group, generates a data packet with a call announce message, and broadcasts the data packet to all members of the PTT communication group. .

The data packet with the call announce message is received by the base station 104 serving the first user and the base station 104 examines the TOS field of the header of the data packet. The base station 104 identifies the data packet containing the time sensitive message and sends the data packet to the wireless device of the first user via the signaling channel. If the wireless device is valid, the base station again sends a call accept message as shown in FIG. The other steps of FIG. 2 are similarly carried out, and data packets supporting these steps are sent on a dedicated channel or signaling channel depending on the type of message identified by the TOS field.

By sending time sensitive messages over the signaling channel instead of requesting and waiting for a dedicated access channel to be established, the latency of PTT communications can be reduced so that using the PTT feature may entertain the user.

Given that the method is executed on a computer device or wireless communication device of wireless service providers, the method may be performed by a program resident on a computer readable medium, where the program may be executed by another computer device or server having a computer platform. Instructs to execute the steps. The computer readable medium can be the memory of a server and reside in the database to which it is connecting. Moreover, the computer readable medium may be present in a secondary medium that can be loaded into a wireless communication device computer platform such as magnetic disk or tape, optical disk, hard disk, flash memory, or other storage media known in the art.

In the context of FIG. 5, the method may be implemented by operating part (s) of a wireless network, such as, for example, a wireless communication device or server, to execute a sequence of machine-readable instructions. Although these steps are shown in sequence, the method may be implemented in a different sequence or may be implemented as an event driven process. The instructions may be in various types of signal-bearing or data storage primary, secondary, or tertiary media. The medium may include, for example, RAM (not shown) accessible by the components of the wireless network or RAM (not shown) present in the components of the wireless network. Whether included in RAM, diskette, or other secondary storage media, instructions can be stored in DASD storage (eg, conventional "hard drives" or RAID arrays), magnetic tape, electronic read-only memory (eg, ROM, EPROM). Or EEPROM), flash memory cards, optical storage devices (eg, CD-ROM, WORM, DVD, digital optical tape), paper “punch” cards, or other suitable data including digital and analog transmission media. It may be stored on a variety of machine-readable data storage media, such as storage media.

While the invention has been shown and described in detail in connection with the preferred embodiments, those skilled in the art understand that various changes in form and detail are possible without departing from the spirit and scope of the invention as set forth in the claims below. For example, it is understood that the above description is based on audio PTT communication, and that the apparatus, system, and method may be easily modified to support other types of media such as video, data, and the like. Moreover, although elements of the invention may be described or claimed in the singular, the plural may be contemplated unless the limitations in the singular are expressly stated.

Claims (20)

A method of reducing latency in push-to-talk (PTT) communication between a plurality of mobile devices, each mobile device communicating with a wireless communication network via one or more signaling channels and data channels, Receiving from the data communication network a data packet comprising a PTT message and having a header at a wireless signal transmission point; Examining the header of the data packet; And If the header of the data packet has a predetermined value, sending the PTT message to a mobile device over a signaling channel. The method of claim 1, If the header in the data packet does not have the predetermined value, requesting a dedicated access channel to be established between the radio signal transmission point and the mobile station and transmitting the PTT message to the mobile device via the dedicated access channel. Further comprising, push-to-talk (PTT) communication latency reduction method. The method of claim 1, And wherein the predetermined value indicates that the PTT message is a time sensitive PTT message. The method of claim 1, Examining the header of the data packet further comprises examining a predetermined field in the header. The method of claim 1, Embedding the PTT message in a signaling message. An apparatus for reducing latency in push-to-talk (PTT) communication between a plurality of mobile devices, each mobile device communicating with a wireless communication network via signaling channels and data channels, A network interface unit for receiving data packets from a data network, each having a header and comprising a PTT related message; A storage unit for storing a data packet having a header; A controller unit for analyzing the header of the stored data packet; And A wireless interface unit for transmitting said stored data packet to a mobile device via a wireless signal, And if the header of the stored data packet has a predetermined value, transmitting the stored data packet to the mobile device via a signaling channel. The method of claim 6, And if the header of the stored data packet does not have the predetermined value, transmitting the stored data packet to the mobile device over a dedicated access channel. The method of claim 6, And the predetermined value indicates that the PTT related message is a time sensitive PTT message. The method of claim 6, And the controller is further capable of inspecting a predetermined field in the header. The method of claim 6, And the air interface unit embeds the PTT message in a signaling message. An apparatus for reducing latency in push-to-talk (PTT) communication between a plurality of mobile devices, each mobile device communicating with a wireless communication network via signaling channels and data channels, Means for receiving from the data network data packets each having a header and comprising a PTT related message; Means for storing a data packet having a header; Means for analyzing the header of the stored data packet; And Means for transmitting the stored data packet to a mobile device via a wireless signal, And if the header of the stored data packet has a predetermined value, transmitting the stored data packet to the mobile device via a signaling channel. The method of claim 11, And if the header of the stored data packet does not have the predetermined value, transmitting the stored data packet to the mobile device over a dedicated access channel. The method of claim 11, And the predetermined value indicates that the PTT related message is a time sensitive PTT message. The method of claim 11, And means for analyzing the header can further inspect a given field in the header. The method of claim 11, And means for transmitting the stored data packets may further embed the PTT message in a signaling message. A computer program on a computer-readable medium that reduces latency in push-to-talk (PTT) communication between a plurality of mobile devices, each mobile device communicating with a wireless communication network via signaling channels and data channels. The computer program, Receiving from the data communication network a data packet comprising a PTT message and having a header at a wireless signal transmission point; Examining the header of the data packet; And Computer instructions executed by a communication server for performing the step of sending the PTT message to a mobile device via a signaling channel if the header of the data packet has a predetermined value. The method of claim 16, If the header in the data packet does not have the predetermined value, requesting a dedicated access channel to be established between the radio signal transmission point and the mobile station and transmitting the PTT message to the mobile device via the dedicated access channel. To do more, computer program. The method of claim 16, The predetermined value indicates that the PTT message is a time sensitive PTT message. The method of claim 16, Examining the header of the data packet further comprises examining a predetermined field in the header. The method of claim 16, Embedding the PTT message in a signaling message.

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