I. Field
The present application relates generally to wireless communications, and more specifically to methods and systems to facilitate seamless handoffs between incompatible wireless communication networks.
II. Background
Wireless communication systems are widely deployed to provide various types of communication content, such as voice, data, multimedia services, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources such as bandwidth and transmit power. Examples of such multiple-access systems include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, 3GPP Long Term Evolution (LTE) systems, and Orthogonal Frequency Division Multiple Access (OFDMA) systems.
In recent years, users have also started to replace fixed line communications with mobile communications and have increasingly demanded great voice quality, reliable service, and low prices. The mobile communications are often implemented on mobile phone handsets or portable computers such as laptops or hand-held computers. As these devices have increased capabilities, users have desired to have access to data and multimedia services such as streaming video. As the demand for high-rate and multimedia data services rapidly grows, there lies a challenge to implement efficient and robust communication systems with enhanced performance to multiple users.
Although new network technologies are available that provides faster speeds, access networks implementing these technologies, referred to herein as “new access networks”, are not always available. When available, a wireless device will use the new access network. However, if the wireless device is moving between a new access network and a traditional access network not implementing these technologies, inter-technology handoff needs to occur. In cellular telecommunications, the term “handoff” refers to the process of transferring an ongoing call or data session from one channel connected to a network to another. “Seamless” handoff would refer to a session where there is little or no delay associated with the handoff. The term “handover” may also be used to refer to handoff. Preferably, no interruption in service should occur for the user while the transition is occurring. Just as importantly, implementing the handoff mechanism should not require the older access network to be updated.