I. Field of the Invention
The present invention relates generally to wireless networks. Particularly, the present invention relates to RSVP signaling to improve quality of service in wireless data transmissions.
II. Description of the Related Art
ReSerVation Protocol (RSVP) was developed in the mid-90s to combat congestion in data networks by allowing routers to decide in advance whether they could meet the requirements of an application flow. In the RSVP scheme, the routers reserved the desired router resources if they were available. RSVP signaling is currently widely used in Internet protocol (IP) networking equipment to improve the quality of service (QoS) provided to end-users. RSVP, however, is not typically used in wireless data services networks due to operator concerns about scalability and the overhead required to support potentially millions of host-to-host flows.
RSVP requests resources for simplex flows, (i.e., it requests resources in only one direction). Therefore, RSVP treats a sender as logically distinct from a receiver, although the same application process may act as both sender and receiver at the same time. RSVP occupies the place of a transport protocol in the protocol stack. However, RSVP does not transport application data but is an Internet control protocol. Like the implementation of routing and management protocols, an implementation of RSVP will typically execute in the background and not in the data-forwarding path.
RSVP is not a routing protocol. Routing protocols determine where packets get forwarded. RSVP is only concerned with the QoS of those packets that are forwarded in accordance with the routing.
FIG. 1 illustrates a typical wireline network using RSVP signaling. In this network, the sending terminal (101) can be a computer or other type of data terminal. The sending terminal (101) initiates a data session by requesting resources from the network. The network determines which routers (105, 106, 107, and 108) are needed in order to communicate between the sending terminal (101) and the end terminal (110). The required routers are then reserved for the session.
RSVP is useful when QoS needs to be guaranteed for a wireline terminal communicating over a network. However, when a wireless terminal needs to communicate over a wireless interface using an air interface standard such as general packet radio service (GPRS), QoS cannot be guaranteed. There is a resulting unforeseen need for a method to guarantee end-to-end QoS over a wireless network.
The present invention encompasses a process for generating end-to-end quality of service in a network that is coupled to a wireless mobile station. The network is comprised of a plurality of RSVP-enabled routers that are coupled to a base station controller. The base station controller communicates traffic over an air interface to the mobile station. The air interface standard has a quality of service standard that is interfaced to the RSVP-enabled routers.
The process interfaces the air interface quality of service standard with the RSVP-enabled routers. The mobile station then transmits an RSVP message to an end terminal through the base station controller and the plurality of RSVP-enabled routers.
The end terminal transmits an RESV response message back to the mobile station. The base station controller intercepts this message and attempts to set up the wireless resources required for the call. If the controller can set up the resources, it does so and forwards the RESV message to the mobile station. If the controller cannot set up the resources, the RESV message is dropped and the call is not allowed to go through.
In the preferred embodiment, the end terminal is a wireline terminal that is coupled to the network through a wireline interface. In another embodiment, the end terminal is a wireless terminal that is coupled to the network through a base station controller.