Optimization in heterogeneous networks

A heterogeneous wireless communication network includes a home access network with a home network characteristic and a home network policy, and a visiting access network with a visiting network characteristic and a visiting network policy. A packet data node gateway is adapted to communicate with the home access network and the visiting access network over a first communication path. An out-of-band communication path substantially separate from the first communication path is adapted to carry the visiting network policy from the visiting access network to the packet data node gateway. When the terminal is handed off from the home network to the visiting network, the packet data node gateway retrieves the visiting network policy, and the terminal accesses the visiting network over the first communication path using the visiting network policy.

BACKGROUND

In various embodiments, heterogeneous networks are optimized substantially.

2. Description of the Related Art

InFIG. 1is shown a conventional wireless network100. The wireless network100includes a core network102and several heterogeneous access networks104. The core network102may include a packet data node gateway124, which may be, in the alternative, a home agent. The core network102may also include a Flexi ISN 120, connected to a voice over IP facility106comprising an operator's IP services108.

The heterogeneous access networks104may each have different network characteristics. The heterogeneous access networks104, for example, may be characterized as long-term evolution networks, code division multiple access networks, or WiMAX networks, in various embodiments.

In such a wireless network100, a packet control relay function sets policies under which a terminal130accesses a given access network, such as home access network110, or visiting access network126. When the terminal130accesses the visiting access network126, the core network102retrieves the policy appropriate for the visiting access network126from the visiting packet control relay function available on the visiting access network126. The core network102, however, will only be able to retrieve the visiting packet control relay function if the terminal112has gone through full registration on the visiting access network126. If the terminal112has gone through full registration on the visiting access network126, in particular, the visiting policy control relay function will be known.

SUMMARY

In one aspect, a heterogeneous wireless communication network includes a home access network with a home network characteristic and a home network policy, a visiting access network with a visiting network characteristic and a visiting network policy, a packet data node gateway adapted to communicate with the home access network and the visiting access network over a first communication path, the packet data node gateway retrieving the home network policy, a terminal adapted to access the home network over the first communication path using the first network policy, an out-of-band communication path from the visiting access network to the packet data node gateway, the out-of-band communication path substantially separate from the first communication path, the out-of-band communication path adapted to carry the visiting network policy to the packet data node gateway, wherein when the terminal is handed off from the home network to the visiting network, the packet data node gateway retrieves the visiting network policy, and the terminal accesses the visiting network over the first communication path using the visiting network policy.

In another aspect, a method of optimizing usage of a heterogeneous wireless communication network includes providing a home access network with a home network characteristic and a home network policy, providing a visiting access network with a visiting network characteristic and a visiting network policy, the visiting network characteristic being different from the home network characteristic, retrieving the home network policy at a packet data node gateway, accessing the home access network with a terminal over a first communication path using the home network policy, providing an out-of-band communication path substantially separate from the first communication path from the visiting access network to the packet data node gateway, informing the packet data node gateway of the visiting network policy over the out-of-band communication path, forwarding terminal data from the home access network to the visiting access network, retrieving the visiting network policy at the packet data node gateway, handing the terminal off to the visiting access network, and accessing the visiting network with the terminal over the first communication path using the visiting network policy.

In still another aspect, a method of optimizing usage of a heterogeneous wireless communication network includes providing a first network with a first network policy, providing a second network with a second network policy, retrieving the first network policy at a core network, accessing the first network with a terminal over a first communication path using the first network policy, providing an out-of-band communication path substantially separate from the first communication path from the second network to the core network, informing the core network of the second network policy over the out-of-band communication path, forwarding terminal data from the first network to the second network, retrieving the second network policy at the core network, handing the terminal off to the second network, and accessing the second network with the terminal over the first communication path using the second network policy.

The above-described embodiments of the present invention are intended as examples, and all embodiments of the present invention are not limited to including the features described above.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the case of a fast handoff, using the conventional network shown inFIG. 1, the terminal112may not have gone through full registration at the visiting network126, and the packet data node gateway124may not be aware of the visiting network126, or its packet control relay function. In such a case, the terminal112may be trying to use the quality of service parameters associated with the home packet control relay function to access a network that may not support them. Thus, it would be desirable if the visiting packet control relay function could be updated periodically on the packet data node gateway124, so that the terminal112could use quality of service parameters supported by the visiting access network126.

InFIG. 2is shown a heterogeneous wireless communication network200according to an embodiment of the invention. The wireless communication network200may be similar to the wireless network100shown inFIG. 1, in that it may include a core network202and several heterogeneous access networks204as well. The core network202may include a packet data node gateway228, which may be, in the alternative, a home agent.

The packet data node gateway228may be adapted to communicate with the home access network210and the visiting access network232over a first communication path216. The packet data node gateway228may retrieve the home network policy from the home access network210. In one embodiment, the packet data node gateway228is a home agent.

The core network202may also include a Flexi ISN 224, connected to a voice over IP facility206comprising an operator's IP services208.

The heterogeneous access networks204may each have different network characteristics. The heterogeneous access networks204, for example, may be characterized as long-term evolution networks, code division multiple access networks, or WiMAX networks, in various embodiments.

Among the heterogeneous access networks204may be the home access network210with a home network characteristic and a home network policy. A visiting access network232with a visiting network characteristic and a visiting network policy may also be included among the heterogeneous access networks204.

In Table I is shown an example of various underlying qualities of service that may be supported for a given terminal by a given access network:

TABLE IQoS ParametersNetwork Layer/ElementAPDN-GW/HAXHome Access NetworkYVisiting Access Network
As shown in Table I, quality of service parameter A, which is supported at the packet data node gateway228, is synchronized with quality of service parameter X, at the home access network210, so that they are always the same. In the case of a fast handoff, however, the packet data node gateway228might still be operating at quality of service parameter X, even though the visiting access network232, to which the terminal234has been handed off, only supports quality of service parameter Y.

The wireless communication network200may be accessed by a terminal212. The terminal212may be adapted to access the home access network210over the first communication path216using the first network policy. In this case, since the home access network210is the home access network for the terminal212, the terminal212is assumed to have gone through full registration on the home access network210. Consequently, the packet data node gateway228is presumed to be aware of the home access network210, including the home packet control relay function.

If the terminal212is handed off from the home access network210to the visiting access network232, the terminal212will access the visiting access network232as terminal234. In that case, the packet data node gateway228retrieves the visiting network policy. InFIG. 2, the terminal234represents the terminal after it has been handed off to the visiting access terminal232.

If the terminal212is handed off using fast handoff from the home access network210to the visiting access network232, on the other hand, the packet data node gateway228may not be aware of the quality of service parameters that are supported for a terminal by the visiting access network232. Thus, the terminal234will not be able to access the visiting access network232using quality of service parameters supported by the visiting access network232. The terminal234, rather, may be trying to access the visiting access network232using the quality of service parameters for the home access network210.

In one embodiment, an out-of-band communication path230may be provided from the visiting access network232to the packet data node gateway228. The out-of-band communication path230may be substantially separate from the first communication path. The out-of-band communication path230may be adapted to carry the visiting network policy to the packet data node gateway228, informing the packet data node gateway228of the visiting network policy before the terminal234begins to access the visiting access network232.

In one embodiment, the visiting network policy is obtained dynamically, and updated in real-time. In this embodiment, the packet data node gateway228could synchronize its quality of service parameter A with the quality of service parameter Y required by the visiting access network232, allowing a substantially seamless handoff of terminal234to visiting access network232. The terminal234accesses the visiting network over the first communication path216using the visiting network policy.

In one embodiment, the out-of-band communication path230could be implemented by adding an extra extension to the proxy mobile IP. The extension could send the quality of service parameters of the underlying access network to the packet data network gateway periodically.

In one embodiment, network usage can be optimized in those scenarios where a quality of service parameter X is substantially identical to a quality of service parameter Y, by ensuring that the quality of service parameters are synchronized periodically between the packet data network gateway and the access networks. The network usage can be optimized in this embodiment by reducing the quality of service parameter A at the packet data network gateway228such that the quality of service parameter equals Y instead of X.

InFIG. 3is shown a process300of optimizing usage of a heterogeneous wireless communication network. In a first operation302, a home access network is provided. The home access network has a home network characteristic and a home network policy. In several embodiments, the home network characteristic may be a transmission format, such as code division multiple access, time division multiple access, frequency division multiple access, orthogonal frequency division multiple access, or long-term evolution. In one embodiment, the home network policy may be a level of quality of service, or a quality of service parameter. In one embodiment, the home network policy comprises a home packet control relay function.

Then, the process300moves from the first operation302to the second operation304, in which a visiting access network is provided. The visiting access network has a visiting network characteristic and a visiting network policy. In several embodiments, the visiting network characteristic may be a transmission format, such as code division multiple access, time division multiple access, frequency division multiple access, orthogonal frequency division multiple access, or long-term evolution. In one embodiment, the visiting network characteristic is different from the home network characteristic.

In one embodiment, the visiting network policy may be a level of quality of service, or a quality of service parameter. In one embodiment, the visiting network policy comprises a visiting packet control relay function.

Then, the process300moves from the second operation304to a third operation306, in which the home network policy is retrieved at a packet data node gateway. In another embodiment, the packet data node gateway may be a home agent.

Then, the process300moves from the third operation306to a fourth operation308, in which the home access network is accessed by a terminal over a first communication path using the home network policy. In one embodiment, the first communication path may include control messages, such as control messages used with a proxy mobile IP protocol.

Then, the process300moves from the fourth operation308to a fifth operation310, in which an out-of-band communication path is provided. In one embodiment, the out-of-band communication path comprises an extension to a proxy mobile IP of the terminal. In one embodiment, the out-of-band communication path is carried from the visiting access network to the packet data node gateway on an out-of-band communication path substantially separate from the first communication path. In one embodiment, the out-of-band communication path piggybacks on the first communication path, but has no interaction with control messages carried over the first communication path.

Then, the process300moves from the fifth operation310to a sixth operation312, in which the packet data node gateway is informed of the visiting network policy over the out-of-band communication path.

Then, the process300moves from the sixth operation312to a seventh operation314, in which terminal data is forwarded from the home access network to the visiting access network.

Then, the process300moves from the seventh operation314to an eighth operation316, in which the visiting network policy is retrieved at the packet data node gateway.

Then, the process300moves from the eighth operation316to a ninth operation318, in which the terminal is handed off to the visiting access network.

Finally, the process300moves from the ninth operation318to a tenth operation320, the visiting network is accessed by the terminal over the first communication path using the visiting network policy.

The embodiments can be implemented in computing hardware (computing apparatus) and/or software, such as (in a non-limiting example) any computer that can store, retrieve, process and/or output data and/or communicate with other computers. The results produced can be displayed on a display of the computing hardware. A program/software implementing the embodiments may be recorded on computer-readable media comprising computer-readable recording media. The program/software implementing the embodiments may also be transmitted over transmission communication media. Examples of the computer-readable recording media include a magnetic recording apparatus, an optical disk, a magneto-optical disk, and/or a semiconductor memory (for example, RAM, ROM, etc.). Examples of the magnetic recording apparatus include a hard disk device (HDD), a flexible disk (FD), and a magnetic tape (MT). Examples of the optical disk include a DVD (Digital Versatile Disc), a DVD-RAM, a CD-ROM (Compact Disc-Read Only Memory), and a CD-R (Recordable)/RW. An example of communication media includes a carrier-wave signal.