TWI501668B - A method for mobile multicast and a device thereof - Google Patents

Description

Method and device for mobile multicast

The present invention relates to the field of multicasting, and more particularly to a method for mobile multicast and a device therefor.

With the rapid spread of WiFi terminal devices, WiFi networks have developed rapidly. Especially in China, for example, telecom operators are planning or have built a large number of WiFi hotspots and hotspots in many cities, providing a certain degree of WiFi coverage and providing network access services to WiFi subscribers. For Chinese telecom operators, building a large-scale WiFi/WLAN network has become a basic strategy for them. After the network infrastructure is built, the next step is to provide users with a wide variety of value-added services on these large-scale WiFi/WLAN networks to attract more WiFi users.

Telecom operators have good experience and foundation in transmitting IPTV services over traditional wired networks. Through the WiFi network, traditional IPTV services can be pushed to WiFi user equipment, so WiFi-based mobile IPTV has become the killer application of WiFi. However, there are some technical problems when pushing a conventional IPTV service from a wired network to a wireless WiFi user. Multicast is the basic mechanism for implementing IPTV. However, from the beginning of design, multicast does not consider support for user mobility. When the multicast-based IPTV service is pushed to the WiFi device of the mobile user, there are a series of problems.

Therefore, a mobile multicast solution must be designed for the WiFi network, especially the operator's WiFi network, especially considering the existing IEEE 802.11 mobile support mechanism.

Considering the feasibility and practicality of mobile multicast solutions, various mobile multicast solutions proposed so far have various problems for the actual network requirements of large-scale WiFi/WLAN networks.

1. There are many studies on mobile multicast and wireless multicast, but there are many problems with these research solutions. The main drawback is that these mobile multicast mechanisms rely on Mobile-IPv6 (MIPv6) and Mobile-IPv4 (MIPv4). Second, other studies are more focused on multicast routing. In these scenarios, the tight coupling requirements of mobile multicast and mobile IP (MIP) and specific routing mechanisms greatly limit the application of mobile multicast in real-world network environments. When the actual deployment of mobile IPTV, it was found that the current solution could not adapt to the actual needs of the WiFi network. The simplest example is that MIP-based mobile multicast mechanisms usually do not work if mobile multicast does not involve changes to Layer 3 IP addresses. Therefore, scalability and practical feasibility are necessary for mobile multicast mechanisms.

2. Kai-Wen Cheng et al. ( Design and Analysis of Cooperative Mobile Multicast Protocol (CMMP) for Intermittent Network Connectivity, IEEE Transactions on Wireless Communications, Vol. 8, No. 6, 2009. ) designed a mobile multicast protocol. However, the agreement requires a complex theory of cooperative communication between wireless channels and network elements. It is still in the theoretical research phase and lacks feasibility in actual network deployment.

3. In the IEEE 802.11 protocol series, IEEE 802.11r and IEEE 802.11f are two mechanisms for supporting mobile terminal (MS) mobility to switch between WiFi ingress points. However, IEEE 802.11r and IEEE 802.11f do not support mobile multicast, which hinders the actual deployment of these IEEE 802.11 protocols.

There is thus a need for a method and apparatus for mobile multicast that enables mobile multicast services to be supported in a wireless local area network.

Embodiments of the present invention propose a method and apparatus for mobile multicast to support mobile multicast services in a wireless local area network.

According to an aspect of the present invention, a method for mobile multicast is provided, comprising: receiving a request for a mobile terminal to re-associate; a current progress in providing a service for the mobile terminal while the mobile terminal is using a multicast service When the contact and the target access point to which the mobile terminal is to be re-associated are in the same strong secure network associated network, generating a multicast context information block as an information packet describing the mobile terminal's multicast service; And transmitting the multicast context information block to the target ingress point, so that the multicast service of the mobile terminal can switch to the target ingress point.

According to another aspect of the present invention, a method for mobile multicasting is provided, comprising: receiving a multicast context information block from an active ingress point that is providing service for the mobile terminal, the multicast context information block being the mobile terminal The multicast service performs the described information packet; determines, according to the extracted information, whether there is a multicast group in which the mobile terminal is located, and if not, sends an Internet Group Management Protocol (IGMP) join message to the multicast proxy; The feedback result of the multicast proxy performs a multicast operation to switch the multicast service of the mobile terminal to the target ingress point.

According to still another aspect of the present invention, a method for joining a multicast group is provided, comprising: receiving an IGMP join message from a target ingress point to which the mobile terminal is to re-associate; creating an entry for the target according to the IGMP join message The multicast group in which the mobile terminal is located, and feedback the creation result to the target ingress point, so that the target ingress point can switch the multicast service of the mobile terminal to the target ingress point.

According to still another aspect of the present invention, a multicast context transmission method is provided, including: generating an information packet describing a multicast service being provided for a mobile terminal; and transmitting the information packet to a packet other than providing the multicast service Other access points other than the contacts, so that the multicast service can be seamlessly provided by the other access points.

According to still another aspect of the present invention, an entry point is provided, including: an ingress point transceiver unit, configured to receive a request for reconnection by a mobile terminal; and an association determining unit: configured to determine whether the mobile terminal is using a multicast service And an active access point that is providing service for the mobile terminal and whether the target access point to which the mobile terminal is to be re-associated is within the same strong secure network association network; and a multicast context information block generating unit for In a case where the determination result is yes, a multicast context information block is generated as an information packet describing the multicast service of the mobile terminal, and the multicast destination block transmits the multicast to the target access point. a context information block to enable switching of the mobile terminal's multicast service to the target ingress point.

According to still another aspect of the present invention, an entry point is provided, comprising: an ingress point transceiver unit for receiving a multicast context information block from an active ingress point that is providing service for the mobile terminal, the multicast context The information block is an information packet describing the multicast service of the mobile terminal; the information extracting unit is configured to extract information related to the multicast service from the multicast context information block, and determine whether the mobile presence exists according to the extracted information. a multicast group in which the terminal is located, if not present, an Internet Group Management Protocol (IGMP) join message is sent to the multicast proxy through the incoming point transceiver unit; and a multicast operation unit: for feedback based on the multicast proxy As a result, a multicast operation is performed to switch the multicast service of the mobile terminal to the target ingress point.

According to still another aspect of the present invention, a multicast proxy is provided, comprising: a proxy transceiver unit for receiving an IGMP join message from a target ingress point to which the mobile terminal is to be re-associated; a multicast creation unit for using the IGMP according to the IGMP Adding a message, creating a multicast group where the mobile terminal is located for the target ingress point, and feeding back a creation result to the target ingress point, so that the target ingress point can switch the multicast service of the mobile terminal to the target Entry point.

According to still another aspect of the present invention, a system for mobile multicast is provided, comprising the two types of access points described above, the above-described multicast agent, and a mobile terminal.

With the technical solution proposed by the embodiment of the present invention, mobile multicast services can be supported in a wireless local area network, and in particular, switching of mobile multicast services through IEEE 802.11r and IEEE 802.11f communication protocols is made possible.

The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings, and the details and functions that are not necessary for the present invention are omitted in the description to avoid confusion of the understanding of the present invention.

The IEEE 802.11r and 802.11f protocols in the IEEE 802.11 protocol series are two protocols that enable WiFi/WLAN users to make fast moves and handovers. However, current IEEE 802.11r and 802.11f do not support mobile multicast, which hinders the actual deployment of the IEEE 802.11 protocol. An illustrative description will be made below for the IEEE 802.11 protocol. However, it should be appreciated that the following technical solutions can also be applied to other protocols, such as the Wireless Ingress Control and Configuration (CAPWAP) protocol.

In an embodiment of the present invention, a system for mobile multicast is proposed. As shown in FIG. 1, the system includes two ingress point devices (APs), a multicast agent, and a mobile terminal (MS). . A person skilled in the art should understand that FIG. 1 is only a schematic system diagram illustrating an embodiment of the present invention. In an actually deployed system, there may be multiple APs, multiple multicast agents, and multiple MSs, and the system structure may also be more complicated. In the following description, it is assumed that AP1 is the current AP that is serving the MS, and AP2 is the target AP to which the MS is to be re-associated.

An access point device (AP) is also proposed. As shown in FIG. 2, the AP includes an AP transceiver unit 210 for receiving a request for reassociation by the MS. The association determining unit 220 is configured to determine whether the MS that requests the re-association is using the multicast service and whether the current AP and the target AP are in the same strong secure network association (RSNA) network. The MCB generating unit 230 is configured to generate a multicast context block (MCB) when the determination result of the association determining unit is yes. The MCB is a group of information describing the multicast service that the MS is using.

The AP further includes an information extracting unit 240, configured to extract information related to the multicast service (ie, IPTV/multicast information in the MCB) from the MCB if the AP is the target AP to which the MS is to be re-associated. According to the information, it is detected whether the AP has the multicast group in which the MS is located. If not, the AP transceiver unit 210 sends an IGMP join message to the multicast proxy of the network to join the MCB. The multicast group where the MS is located.

The AP also includes a multicast operation unit 250 for performing a multicast operation, such as joining a multicast group in which the MS is located.

The AP further includes an association operation unit 260 for re-associating the MS with the AP in the case that the AP is the target AP to which the MS is to be re-associated, such that the multicast service is provided to the MS through the AP.

A multicast proxy is also provided. As shown in FIG. 3, the multicast proxy includes a proxy transceiving unit 310 for receiving a message (eg, an IGMP multicast join message) sent by a target AP to which the MS is to re-associate. The multicast creation unit 320 is configured to add the MS to the multicast group according to the received message, that is, create a multicast group where the MS is located for the target AP.

Although the AP and the multicast agent of the embodiment of the present invention have been described above in the form of separate functional modules, each of the elements shown in FIGS. 2 and 3 can be implemented by a plurality of devices in practical applications, as shown. Multiple components can also be integrated into a single wafer or a device in practical applications. The AP and multicast agent can include any unit and device for other purposes. It is also possible to use different elements of the AP described above at different stages of the multicast service, or to place different elements in different devices, for example, if the AP is the current AP that is serving the MS, then It is the association judgment unit 220 and the MCB generation unit 230, and if the AP is the target AP, the information extraction unit 240, the multicast operation unit 250, and the associated operation unit 260 are used, and therefore, different devices may include only those that need to be used. element.

The above AP and multicast agent will be described in detail below with reference to the mobile multicast method shown in FIG.

4 is a flow chart of a mobile multicast method according to an embodiment of the present invention.

In step 410, the AP transceiving unit 210 of AP1 (i.e., the current serving AP of the MS) receives a request to re-associate from the MS.

In step 420, the association determining unit 220 of AP1 determines: Is the MS now using multicast services and Whether AP1 and target AP2 (ie, the target AP to which the MS is to be re-associated) are within the same RSNA network.

Determination of step 420 This means that if a handover occurs in the future, for example, when the MS switches from AP1 to AP2, the IPTV/multicast service of the MS also switches seamlessly from AP1 to AP2.

If one of the above two judgments does not hold, the flow proceeds to step 480 to directly re-associate the MS to AP2.

If both of the above determinations are true, the flow proceeds to step 430, and the MCB generating unit 230 in the AP1 generates the MCB and transmits it to the AP2 through the AP transceiver unit 210.

Taking the IEEE 802.11 r/f protocol as an example, the MCB can be defined to describe and include multicast information of the MS. An example of the definition of the MCB is shown below:

MCB <

MS's MAC address

Join the IP address of the multicast group;

QoS parameters of the IPTV channel;

Safety parameters, etc.

...‧

>

In this example, the MCB includes the MAC address of the MS, the IP address of the join multicast group, the QoS parameters of the IPTV channel, and the like. However, it should be emphasized that the size and content of the MCB are not fixed. In other examples, the MCB may be dynamically extended according to actual needs to include more multicast information and/or IPTV parameters.

And if the content of the MCB only includes the MAC address of the MS, which means that the MS does not use any IPTV/multicast, such MCB is invalid.

Returning to FIG. 4, in step 440, the AP transceiver unit 210 of the AP2 receives the MCB sent by the AP1, and the information extraction unit 240 extracts the information related to the multicast service (ie, IPTV/multicast information) from the MCB. .

In step 450, the information extraction unit 240 of the AP2 detects, according to the information, whether the AP2 has the multicast group in which the MS is located.

If not, in step 460, the AP transceiver unit 210 sends a standard IGMP join message to the multicast proxy of the network to join the multicast group in which the MS included in the MCB is located.

The multicast creation unit 320 in the multicast agent creates a multicast group in which the MS is located for the target AP (ie, AP2), and feeds back the result to the AP2. The multicast group creation here can be performed according to the multicast group creation process in the specific agreement, and will not be further elaborated here.

In step 470, the multicast operation unit 250 in the AP2 performs a multicast operation according to the feedback result from the multicast agent, where the multicast operation includes a conventional multicast operation such as joining a multicast group, registration, or the like. The feedback here can be a standard message in a multicast business process.

In step 480, the associated operating unit 260 in AP2 re-associates the MS from AP1 to AP2 so that the IPTV/multicast service can continue to be provided to the MS through AP2.

The mobile multicast method of the present invention will be described below by taking IEEE 802.11r and IEEE 802.11f as examples.

Example 1

According to IEEE 802.11r, an MCB can be created in a resource information memory (RIC) embedded in an IEEE 802.11 message. A specific method may be to extend the RIC to carry the MCB delivered by the resource request message. In the IEEE 802.11 RSNA, the resource request and the resource response are exchanged after the pairwise temporary key (PTK) is established, and the resource request and the resource response are protected by the integrity check of the message to ensure the security of the MCB. The IEEE 802.11r frame structure after MCB extension is as follows:

The structure of the IEEE802.11r fast BSS transform information element is shown in Table 2:

It can be seen that in the embodiment of the present invention, the frame structure of IEEE 802.11 is extended, and two information elements of "resource information memory-data" and "resource information memory-MCB" are added and "fast BSS transform" is added. The information element has been modified to carry the MCB in the IEEE 802.11 message.

Example 2

A multicast context information block (MCB) can be created in the IAPP-MOVE message of IEEE 802.11f. The Incoming Point Internal Agreement (IAPP) supports the delivery of MS content information between peer APs. Two IAPP messages (IAPP MOVE-notify and IAPP-MOVE.indication) can carry content information and can carry the MCB in the extended content block of the MOVE-response packet. In the IAPP MOVE-response packet indicating the current multicast traffic of the MS, the MCB must be visible.

When receiving IAPP MOVE-notify and IAPP-MOVE.indication, the multicast operation unit 250 of AP1 will generate an IAPP MOVE-response including all the multicast content information created by AP1:

IAPP-MOVE.response{

MAC address,

serial number,

AP address,

Multicast context information block

status

}

After receiving the service primitive, AP1 will refer to all relevant content of the MS to be re-associated to the peer IAPP entity of AP2 (after the handover is completed), wherein AP2 is sent by sending IAPP The MOVE-response packet is associated with the MS, and after the response occurs, AP1 may discard any multicast content for the MS identified by the MAC address parameter.

It should be appreciated that the techniques provided by embodiments of the present invention are not only applicable to IEEE 802.11 r/f, but also to other systems that can implement mobile multicast, for example, when using wireless ingress point control and configuration (CAPWAP). In the case of agreement, it is only necessary to provide the access controller (AC) with the same functions as those used by the AP in the above technical solution, and the implementation of the present invention can be realized by using a message similar to that used in the above technical solution. The technical solution disclosed by the example.

Those skilled in the art will readily recognize that the various steps of the above methods can be implemented by programming a computer. Herein, some embodiments also include a machine readable or computer readable program storage device (eg, a digital data storage medium) and an encoded machine executable or computer executable program instructions, wherein the instructions perform some of the above methods or All steps. For example, the program storage device can be a digital memory, a magnetic storage medium (such as a magnetic disk and a magnetic tape), a hardware or an optically readable digital data storage medium. Embodiments also include a programming computer that performs this step of the above method.

The description and drawings merely illustrate the principles of the invention. It will be appreciated that those skilled in the art are able to devise various structures, and the various embodiments are not described herein. In addition, all of the example examples mentioned herein are explicitly used primarily for teaching purposes to assist the reader in understanding the principles of the present invention and the concepts promoted by the inventors, and should be construed as not specifically Example examples and conditions. Moreover, all statements herein reciting principles, aspects, and embodiments of the invention, as well as specific examples thereof

The above description is only used to implement the embodiments of the present invention, and those skilled in the art should understand that any modification or partial substitution without departing from the scope of the present invention should fall within the scope defined by the scope of the present invention. The scope of protection of the present invention should be based on the scope of protection of the scope of the patent application.

210. . . AP transceiver unit

220. . . Associated judgment unit

230. . . MCB generating unit

240. . . Information extraction unit

250. . . Multicast operating unit

260. . . Associated operating unit

310. . . Proxy transceiver unit

320. . . Multicast group creation unit

AP1-AP2. . . Entry point

MS. . . Mobile terminal

The advantages of the present invention will become readily apparent from the following description in conjunction with the accompanying drawings in which:

1 shows a schematic diagram of a system for mobile multicasting in accordance with an embodiment of the present invention;

2 is a block diagram showing the structure of an access point device according to an embodiment of the present invention;

FIG. 3 shows a flow chart of a mobile multicast method in accordance with an embodiment of the present invention.

4 is a flow chart of a mobile multicast method according to an embodiment of the present invention.

210. . . AP transceiver unit

220. . . Associated judgment unit

230. . . MCB generating unit

240. . . Information extraction unit

250. . . Multicast operating unit

260. . . Associated operating unit

Claims (10)

A method for mobile multicasting, comprising: receiving a request for a mobile terminal to re-associate; a current ingress point in which the mobile terminal is using a multicast service, and the mobile station is providing a service and the mobile terminal is about to be re-associated When the target access point is in the same strong secure network association network, a multicast context information block (MCB) is generated as an information packet describing the mobile terminal's multicast service; according to actual needs The content of the multicast context information block is dynamically expanded; and the dynamically extended multicast context information block is sent to the target ingress point to enable the mobile terminal's multicast service to switch to the target ingress point. The method of claim 1, wherein the transmitting the multicast context information block to the target homing point comprises: transmitting the multicast context information block to the target by extension of an IEEE 802.11 frame structure The entry point; or the multicast context information block is sent to the target ingress point in an Ingress Point Internal Agreement (IAPP) message. A method for mobile multicasting, comprising: receiving a multicast context information block from an active ingress point that is providing service for a mobile terminal, the multicast context information block being an information packet describing a multicast service of the mobile terminal And dynamically expanding; determining whether the mobile terminal exists according to the received context information block a multicast group, if not present, sending an Internet Group Management Protocol (IGMP) join message to the multicast proxy; and performing a multicast operation according to the feedback result of the multicast proxy to multicast the mobile terminal Switch to the target entry point. The method of claim 3, further comprising: after the multicast service of the mobile terminal is switched to the target access point, completing the re-association of the mobile terminal to the target access point. A multicast context transmission method includes: generating a dynamically extended multicast context information block of an information packet describing a multicast service being provided for a mobile terminal; transmitting the multicast context information block to the multicast service Other entry points other than the entry point to enable the multicast service to be provided by the other entry point. An ingress point device for mobile multicast, comprising: an ingress point transceiver unit, configured to receive a request for reconnection by the mobile terminal; and an association determining unit: configured to determine whether the mobile terminal is using a multicast service and is Whether the current access point of the service provided by the mobile terminal and the target access point to which the mobile terminal is to be re-associated is in the same strong secure network association network; and a multicast context information block generating unit for determining according to the association As a result of the affirmative determination of the unit, a dynamically extended multicast context information block is generated as an information packet describing the multicast service of the mobile terminal, and the transmitting and receiving unit transmits the same to the target ingress point. Dynamically extended The context information block is multicast to enable the multicast service of the mobile terminal to be switched to the target ingress. The access point device according to claim 6, wherein the current access point and the target access point are in an access point or a wireless access point control and configuration protocol used in the IEEE 802.11 protocol series. Incoming controller. An ingress point device for mobile multicast, comprising: an ingress point transceiver unit for receiving dynamically extended multicast context information blocks from an active access point that is providing services for the mobile terminal, the dynamically expanding The multicast context information block is an information packet describing the multicast service of the mobile terminal; the information extracting unit is configured to extract information related to the multicast service from the dynamically extended multicast context information block, and according to the The extracted information determines whether there is a multicast group in which the mobile terminal is located, and if not, sends an Internet Group Management Protocol (IGMP) join message to the multicast proxy through the incoming point transceiver unit; and the multicast operation unit: According to the feedback result of the multicast proxy, a multicast operation is performed to switch the multicast service of the mobile terminal to the target ingress point. According to the access point device of claim 8, the method further includes: a re-association unit, configured to re-associate the mobile terminal to the target after switching the multicast service of the mobile terminal to the target access point Incoming point to continue to provide multicasting for the mobile terminal through the target access point Business. The access point device according to claim 8 or 9, wherein the current access point and the target access point are the access point or wireless access point control and configuration used in the IEEE 802.11 protocol series Incoming controller in the agreement.