Method and device for mobile multicast
Method and a device for mobile multicast technical field
The present invention relates to multicast field, in particular it relates to method and a device for mobile multicast.Background technology
With the quick popularization of WiFi terminal equipment, WiFi network is developed rapidly.Particularly in China, such as, telecom operators are planning in many cities or constructed numerous Wi-Fi hotspot and hot-zone are covered there is provided a certain degree of WiFi, and network insertion service is provided to WiFi subscribed users.For the telecom operators of China, build large-scale WiFi/WLAN networks and become their elementary tactics.After network infrastructure has been built, next step it is mostly important and it is urgent provide a user rich and varied value-added service on these large-scale WiFi/WLAN networks, to attract more WiFi users.
Telecom operators transmit IPTV business on conventional wired networks has good experience and basis, pass through WiFi network, traditional IPTV service can be pushed on WiFi user equipmenies, so the mobile IPTV based on WiFi has become WiFi Killer application.However, when traditional IPTV service is pushed from cable network to wireless WiFi user, there are some technical problems.Multicast is the fundamental mechanism for realizing IPTV, however, at the beginning of the design, multicast does not just account for the support to user mobility.When the IPTV service based on multicast is shipped in the WiFi equipment of mobile subscriber, it can come up against a series of problems.
Therefore, it is necessary to design a kind of mobile multicast solution for the WiFi network of WiFi network, particularly operator, it is important to consider to combine the existing mobile support mechanisms of IEEE 802.11.
In view of the feasibility and practicality of mobile multicast solution, for the real network demand of extensive WiFi/WLAN networks, the various mobile multicast solutions proposed so far there are problems that various.
1st, mobile multicast and wireless multicast are directed to now with many researchs, but there are many problems in the scheme of these researchs.Main defect is that the mechanism of these mobile multicasts is to rely on mobile-IPv6 (Μ Ι Ρ ν 6) and mobile-IPv4 (secondly, some other is studied then more focused on Multicast Routing MIPv4.In these schemes, the close coupling requirement of mobile multicast and mobile IP (MIP) and specific routing mechanism significantly limit mobile multicast and be applied in real network environment.When actual deployment moves IPTV, it is found that current solution does not adapt to the actual demand of WiFi network.Simplest example is, if mobile multicast is not related to the change of three layers of IP address, and the mobile multicast mechanism based on MIP generally can not work.Therefore, for mobile multicast mechanism, scalability and actually may be used
Row is must.
2nd, 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. a kind of mobile multicast protocol 6,2009.) is devised.However, the agreement needs to carry out the complexity theory of communication for coordination between wireless channel and network element, also in theoretical research stage, lack feasibility in real network deployment.
3rd, in the protocol suites of IEEE 802.11, k the and IEEE 802.11f of IEEE 802.1 are the two kinds of support mobile terminals provided(MS) the mobile mechanism switched between WiFi access points.However, IEEE 802.11r and IEEE 802.11f do not support mobile multicast, which prevent the actual deployment of these agreements of IEEE 802.11.
Thus need a kind of method and a device for mobile multicast, enabling support mobile multicasting service in a wireless local area network.The content of the invention
Embodiments of the invention propose a kind of method and a device for mobile multicast, to support mobile multicasting service in a wireless local area network.
According to an aspect of the invention, it is proposed that a kind of method for mobile multicast, including:Receive the request that mobile terminal is associated again;Multicast service is used in the mobile terminal, and for the mobile terminal provide service current access point and the target access that will be associated with again of the mobile terminal in same Robust Secure Network related network when, produce the multicast context block of information for the information block being described as the multicast service to the mobile terminal;And the multicast context block of information is sent to the target access, to cause the multicast service of the mobile terminal to can switch to the target access.
According to another aspect of the invention, it is proposed that a kind of method of mobile multicast, including:Multicast context block of information is received from the current access point for providing service for the mobile terminal, the multicast context block of information is the information block that the multicast service of the mobile terminal is described;Information according to being extracted judge whether the mobile terminal where multicast group, if it does not, to multicast agent send IGMP(IGMP message) is added;And multicast operation is carried out according to the feedback result of the multicast agent, the multicast service of the mobile terminal is switched to the target access.
According to another aspect of the invention, it is proposed that it is a kind of add multicast group method, including:The target access that will be associated with again from mobile terminal receives IGMP and adds message;Message is added according to the IGMP, is described
Target access creates the multicast group where the mobile terminal, and creates result to target access feedback, to enable the target access that the multicast service of the mobile terminal is switched into the target access.
According to another aspect of the invention, it is proposed that a kind of multicast context transmission method, including:Generate the information block to being described for the multicast service that mobile terminal is provided;By described information packet transmission to other access points in addition to the access point for providing the multicast service, to enable the multicast service seamlessly to transfer to other access points to provide.
According to another aspect of the invention, it is proposed that a kind of access point, including:Access point Transmit-Receive Unit, for receiving the request that mobile terminal is associated again;Associate judging unit:For judging whether the mobile terminal provides target access that the current access point of service and the mobile terminal will be associated with again using multicast service and for the mobile terminal whether in same Robust Secure Network related network;And multicast context block of information generation unit, for in the case where judged result is all to be, produce the multicast context block of information for the information block being described as the multicast service to the mobile terminal, and the multicast context block of information is sent to the target access by described access point Transmit-Receive Unit, enable to the multicast service of the mobile terminal being switched to the target access.
In accordance with a further aspect of the present invention, it is proposed that a kind of access point, including;Access point Transmit-Receive Unit, for receiving the multicast context block of information from the current access point that service is provided for the mobile terminal, the multicast context block of information is the information block that the multicast service of the mobile terminal is described;Information extraction unit, for extracting the information relevant with multicast service from the multicast context block of information, and the multicast group according to where the information extracted judges whether the mobile terminal, if it does not, sending IGMP to multicast agent by described access point Transmit-Receive Unit(IGMP message) is added;And multicast operation unit:For the feedback result according to the multicast agent, carry out multicast operation the multicast service of the mobile terminal is switched into the target access.
In accordance with a further aspect of the present invention, it is proposed that a kind of multicast agent, including:Transmit-Receive Unit is acted on behalf of, the target access for that will be associated with again from mobile terminal receives IGMP and adds message;Multicast creating unit, for adding message according to the IGMP, the multicast group where the mobile terminal is created for the target access, and result is created to target access feedback, to enable the target access that the multicast service of the mobile terminal is switched into the target access.
In accordance with a further aspect of the present invention, it is proposed that a kind of system for mobile multicast, including two kinds of above-mentioned access points, above-mentioned multicast agent and mobile terminal.
The technical scheme proposed by embodiments of the invention, mobile multicasting service can be supported in a wireless local area network, especially so that multicast service is moved by 1r the and IEEE 802.11f communication protocols of IEEE 802.1 is switching to possibility.Brief description of the drawings
According to the following description with reference to accompanying drawing, advantages of the present invention will become prone to understand, wherein-Fig. 1 shows the schematic diagram of the system for mobile multicast according to embodiments of the present invention;
Fig. 2 shows the structured flowchart of access point apparatus according to embodiments of the present invention;
Fig. 3 shows the flow chart of mobile multicasting method according to embodiments of the present invention.Specific embodiment
With reference to the accompanying drawings to a preferred embodiment of the present invention will be described in detail, it is unnecessary details and function for the present invention to eliminate in the course of the description, to prevent the understanding of the present invention from causing to obscure.
Agreement IEEE 802.11r and 802.11f in the protocol suites of IEEE 802.11 are two kinds and WiFi/WLAN user are spouted quickly mobile and switching the agreement of row.However, the current ι and 802.11f of Ι Ε Ε Ε 802.11 do not support mobile multicast, which prevent the actual deployment of the agreements of IEEE 802.11.Exemplary description will be carried out for the agreements of IEEE 802.11 below.But it will be appreciated that following technical scheme can also be used for other agreements, such as WAP control and configuration(CAPWAP) agreement.
In an embodiment of the present invention, it is proposed that a kind of system for mobile multicast, as shown in figure 1, the system includes two access point apparatus(AP), a multicast agent and a mobile terminal(MS ).Art technology personnel should be understood that Fig. 1 is illustrative of the invention the schematic system diagram of embodiment, in the system of actual deployment, can have multiple AP, multiple multicast agents and multiple MS, the structure of system can also be more complicated.In the following description, it is assumed that API is the current AP that service is being provided for MS, and AP2 is the target AP that MS will be associated with again.
It also proposed a kind of access point apparatus(AP), as shown in Fig. 2 the AP includes AP Transmit-Receive Units 210, for receiving the request that MS is associated again.Judging unit 220 is associated, for judging whether whether the MS that request is associated again is associated in (RSNA) network using multicast service and current AP with target AP in same Robust Secure Network.MCB generation units 230, for generating multicast context block of information when the judged result of judging unit is associated all to be(MCB, multicast context block) MCB is that MS is made
The information block that multicast service is described.
The AP also includes information extraction unit 240, in the case of being the target AP that MS will be associated with again in the AP, and the information relevant with multicast service is extracted from MCB(That is, the IPTV/ multicast informations in MCB)And according to the information, detect whether the AP has had the multicast group where the MS, if there is no, IGMP is then sent to the multicast agent of the network by AP Transmit-Receive Units 210 and adds message, to add the multicast group where the MS included in MCB.
The AP also includes multicast operation unit 250, for carrying out multicast operation, e.g., adds multicast group where MS.
The AP also includes associated operation unit 260, and in the case of being the target AP that MS will be associated with again in the AP, MS is associated again with the AP so that provide multicast service to MS by the AP.
A kind of multicast agent is additionally provided, as shown in figure 3, the multicast agent includes acting on behalf of Transmit-Receive Unit 310, for receiving the message transmitted by the target AP that MS will be associated with again(Such as, IGMP multicast join messages).Multicast creating unit 320, for MS to be added into the multicast group in advance according to the message received, i.e. the multicast group where MS is created for target AP.
Although the AP and multicast agent of the embodiment of the present invention are described in the form of the functional module of separation above, but each component shown in Fig. 2 and Fig. 3 can realize that the multiple components shown can also be integrated in chip piece or an equipment in actual applications with multiple devices in actual applications.The AP and multicast agent may include any unit and device for other purposes.Component that can also be different in the different phase of multicast service uses AP described above, or be placed on different components in different equipment, for example, if AP is the current AP that service is being provided for MS, then using to be association judging unit 220 and MCB generation units 230, and if AP is target AP, then use information extraction unit 240, multicast operation unit 250 and associated operation unit 260, therefore, the component for needing to use can be only included in different equipment.
Below with reference to the mobile multicasting method shown in Fig. 4, above-described AP and multicast agent are described in detail.
Fig. 4 is the flow chart of the mobile multicasting method of the embodiment of the present invention.
In step 410, API (gp, MS current service AP) AP Transmit-Receive Units 210 receive the request associated again from MS.
In step 420, API association judging unit 220 judges:1. MS now whether using multicast service and 2. API and target AP2 (that is, the target AP that MS will be associated with again) whether in same RSNA networks.
Walk rapid 420 judgement is 1. it is meant that following in the event of switching, such as when MS is switched to AP2 from API, MS IPTV/ multicast services also will switch seamlessly to AP2 from API.
If two above judge in have one it is invalid, flow proceeds to step 480, and MS is directly associated with into AP2 again.
If two above judges all to set up, the generation MCB of MCB generation units 230 that flow proceeds in step 430, API, and it is sent by AP Transmit-Receive Units 210 to AP2.
By taking the r/f agreements of IEEE 802.11 as an example, MCB can be defined to describe and the multicast information including MS.An example being defined to MCB has been illustrated below:
MCB <
MS MAC Address
Add the IP address of multicast group;,
The qos parameter of IPTV channel;
Security parameter etc.;
>
In this example, MCB includes the contents such as MS MAC Address, IP address, the qos parameter of IPTV channel of addition multicast group.However, it is to be emphasized that MCB size and content are not fixed, dynamic expansion can be carried out to MCB according to actual needs in other examples, with including more multicast informations and/or IPTV parameters.
And if MCB content only includes MS MAC Address, it means that the MS does not use any IPTV/ multicasts, therefore such MCB is invalid.
Referring back to Fig. 4, in step 440, AP2 AP Transmit-Receive Units 210 receive the MCB that API is sent, and information extraction unit 240 extracts the information relevant with multicast service included from the MCB(SP, IPTV/ multicast information).
In step 450, multicast group of the AP2 information extraction unit 240 according to where whether infomation detection AP2 has the MS.
If it does not exist, then in step 400, the IGMP for sending standard to the multicast agent of the network by Α Ρ Transmit-Receive Units 210 adds message, to add the multicast group where the MS included in MCB.
Multicast creating unit 320 in multicast agent creates the multicast group where MS for target AP (that is, AP2), and to AP2 feedback results.Here multicast group, which is created, to be carried out according to the multicast group visioning procedure in specific agreement, be not further elaborated herein.
In step 470, the multicast operation unit 250 in AP2 after the feedback result of multicast agent according to multicast operation is carried out, and multicast operation here includes adding the conventional multicast operation such as multicast group, registration.Here feedback result can be the standard message in multicast service flow.
In step 480, MS is associated with AP2 by the associated operation unit 260 in AP2 again from API, and IPTV/ multicast services are provided so as to continue as MS by AP2.
The mobile multicasting method of the present invention is described using the lr of IEEE 802.1 and the If of IEEE 802.1 as example below.Example one
According to the lr of IEEE 802.1, resource information memory that can be embedded in the message of IEEE 802.11(RIC MCB is created in).Specific method can be that RIC is extended to carry the MCB transmitted by resource request message.In IEEE 802.11 RSNA, pair temporal key is being set up(PTK just exchange resource request and resource response, and resource request and resource response are protected by the integrity check of message after), to ensure MCB safety.IEEE 802.11r frame structures after MCB extends are as follows:
The lr frame structures of IEEE 802.1 after the extension of table 1
The structure of IEEE802.Ur fast Bs SS information convertings member therein is as shown in table 2:
The fast B SS information convertings of table 2. member
First ID length MS MAC service multicast groups 1PTV parameter safety ginseng
58 address ip Milk channel QoS numbers
It can be seen that, in an embodiment of the present invention, IEEE 802.11 frame structure is extended, add " resource information memory-data " and " resource information memory-MCB " two information words and " fast B SS information convertings member " is modified, so as to carry MCB in IEEE 802.11 message.
Example 2
Multicast context block of information can be created in the If of IEEE 802.1 IAPP-MOVE message(MCB) .Access point internal agreement(IAPP the transmission of the MS content informations between equity AP) is supported.Two IAPP message (IAPP MOVE-notify and IAPP-MOVE.indicatkm) can carry content information, and can carry MCB in the extension content blocks that MOVE-response is grouped.In the IAPP MOVE-response packets indicated MS current multicast business, MCB must be observable.
When receiving IAPP MOVE-notify and IAPP-MOVE.indication, API multicast operation unit
250 include the IAPP MOVE-response for all multicast content information that API is created by generating:
IAPP-MOVE.response {
MAC Address,
Sequence number,
AP addresses,
Multicast context block of information
State
}
Receiving the business primitive(Primitive after), API is involved in all related contents for the MS that will be associated again and is forwarded in AP2 reciprocity IAPP entities(After the completion of the handover), wherein, AP2 is to be associated by sending IAPP MOVE-response packets with MS, and after response generation, API is discardable any for the MS recognized by MAC Address parameter multicast content.
It will be appreciated that, the technology that the embodiment of the present invention is provided is applied not only to the l r/f of IEEE 802.1, it can be equally used for can be achieved other systems of mobile multicast, for example,, only need to be to access controller when being controlled using WAP and configuring (CAPWAP) agreement(AC) provide with above-mentioned technical proposal in assembly function identical component used in AP, and use the message similar with the message used in above-mentioned technical proposal, just can realize the embodiment of the present invention public affairs Jian technical scheme.
Those skilled in the art be should be readily recognized that, the different step of the above method can be realized by programmed computer.Here, some embodiments equally include machine readable or computer-readable program storage device(Such as, number
Digital data storage medium)And the programmed instruction that encoding machine is executable or computer is executable, wherein, the instruction performs some or all steps of the above method.For example, program storage device can be digital storage, magnetic storage medium(Such as Disk and tape), hardware or readable digital data storage medium of light.Embodiment equally includes the programmed computer for performing the step of the above method.
Description and accompanying drawing only show the principle of the present invention.Thus, it will be appreciated that those skilled in the art can advise different structures, although these different structures are not expressly recited or shown here, but embody the principle of the present invention and be included within its spirit and scope.In addition, it is all referring herein to example be clearly mainly served only for teaching purpose to help reader to understand the design of promotion this area that the principle of the present invention and inventor are contributed, and should be interpreted it is not the limitation to these examples and condition that are specifically mentioned.In addition, all principle, the statement of aspect and embodiment and its specific examples for mentioning the present invention are comprising including its equivalent herein.
Above description is only used for realizing embodiments of the invention; it should be appreciated by those skilled in the art; the any modification or partial replacement of the scope of the present invention is not being departed from; the scope that the claim of the present invention should be belonged to limit; therefore, protection scope of the present invention should be defined by the protection domain of claims.