Application-layer multicast for mobile users in diverse networks
View Patent ↗As multicast services become prevalent, it is important to find viable solutions for multicasting to mobile nodes. This problem is complicated by the necessity to support multicast services over existing backbone and access networks that may have varying network and/or link layer multicasting capabilities. While most work on supporting multicast services focuses on the IP layer solution, the present invention presents an application-layer approach for providing multicast services to mobile users traversing networks with diverse multicast capabilities. The present invention places multicast proxies in the backbone and access networks to support several multicast-related functions at the application layer including the creation of virtual networks for dynamically tunneling through non-multicast-capable networks.
1. A telecommunications network for providing multicast services for distributing content to mobile users, said mobile users moving between a plurality of access networks, said telecommunications network comprising:
at least one media server for providing content;
a virtual network of backbone proxies that communicate with said media server and acting as a gateway between said media server and said mobile users; and
local proxies that communicate with said backbone proxies and act as a gateway between said mobile users and said backbone proxies, said local proxies are located at the edge of the access networks and a backbone network, wherein end-to-end communication between said at least one media server and said mobile users is controlled at an application layer.
2. A telecommunications network according to claim 1 , wherein said backbone proxies communicate between each other by means of a tunneling technique.
3. A telecommunications network according to claim 2 , wherein said tunneling technique is automatic multicast tunneling.
4. A telecommunications network according to claim 2 , wherein said tunneling technique is UDP multicast tunneling protocol.
5. A telecommunications network according to claim 1 , wherein said backbone proxies intercept multicast packets sent by said media server and forwards said packets along a multicast route in said virtual network.
6. A telecommunications network according to claim 5 , wherein said multicast route is pre-configured.
7. A telecommunications network according to claim 1 , wherein said local proxies advertise multicast services to said mobile users.
8. A telecommunications network according to claim 1 , wherein said local proxies intercept service requests from said mobile users and route said requests to said media servers through said virtual network.
9. A telecommunications network according to claim 1 , wherein said access network is not multicast-enabled and said local proxies provide multicast information to said mobile users using a tunneling technique.
10. A telecommunications network according to claim 1 , wherein said network utilizes IP multicast when available.
11. A telecommunications network according to claim 1 , wherein a multicast group is identified by both a source IP address provided by said media server and an IP multicast address assigned by said backbone proxies.
12. A telecommunications network according to claim 1 , wherein said media server provides location-specific information and the mobile users geographical location is determined by GPS technology.
13. A method for a mobile user to join a multicast group, said mobile users moving between a plurality of access networks, said method comprising:
establishing a telecommunications network for providing multicast services for distributing content to mobile users comprising at least one media server for providing content, a virtual network of backbone proxies that communicate with said media server and acting as a gateway between said media server and said mobile user, and local proxies that communicate with said backbone proxies and act as a gateway between said mobile user and said backbone proxies, said local proxies are located at the edge of the access networks and a backbone network, said method comprising:
said local proxies advertising said content provided by said media server;
said mobile user sending a request for said content;
said local proxies receiving said request and forwarding said request to said media server through said virtual network;
said media server sending said content to said local proxies through said virtual network; and
said local proxies sending said content to said mobile users, wherein end-to-end communication between said at least one media server and said mobile users is controlled at an application layer.
14. A method according to claim 13 , wherein said local proxies use a tunneling technique to send said content to said mobile users.
15. A method according to claim 13 , wherein said plurality of access networks is selected from a group consisting of non-multicast enabled networks and multicast enabled networks.
16. A method according to claim 15 , wherein at least one of each plurality of access networks is a non-multicast enabled network.