Method and system for load-balancing across multiple access networks

1. A method comprising:

determining loading information of a plurality of radio access networks that are accessible by a terminal, wherein the radio access networks employ different radio access technologies; and

outputting a list of candidates from the radio access networks based on the loading information for use by the terminal,

wherein the loading information corresponds to a universal loading indicator, the universal loading indicator including a plurality of loading coefficients, each loading coefficient defining a ratio between real-time usage of network resources corresponding to a particular radio access network and capacity of the particular radio access network, each loading coefficient being multiplied by a preference weighting element indicating a preferred service application of a service provider.

2. A method of claim 1 , further comprising:

determining whether one of the candidates supports a requested application service of the terminal; and

removing the one candidate from the list if the one candidate does not support the requested application service.

3. A method of claim 1 , further comprising: determining a handover interruption time for one of the candidates;

comparing the determined handover interruption time with a predetermined threshold value; and

removing the one candidate from the list if the determined handover interruption time satisfies a predetermined threshold value.

4. A method of claim 1 , further comprising:

determining a quality of service (QoS) parameter value for one of the candidates; and

removing one of the candidates from the list if the QoS parameter does not satisfy a predetermined QoS parameter value.

5. A method of claim 1 , further comprising:

retrieving a service policy corresponding to the terminal; and

removing one of the candidates from the list based on the service policy.

6. A method of claim 1 , further comprising:

receiving a measurement report associated with one of the candidates; and

removing the one candidate from the list based on the measurement report.

7. A method of claim 1 , wherein the step of determining the loading information includes, obtaining over-the-air measurements relating to loading of the radio access networks, or communicating with one or more of the radio access networks to obtain the loading information.

8. A method of claim 1 , further comprising:

performing a handover to one of the candidates.

9. An apparatus comprising:

selection logic configured to determine loading information of a plurality of radio access networks that are accessible by a terminal, wherein the radio access networks employ different radio access technologies, and the selection logic is further configured to output a list of candidates from the radio access networks based on the loading information for use by the terminal,

wherein the loading information corresponds to a universal loading indicator, the universal loading indicator including a plurality of loading coefficients, each loading coefficient defining a ratio between real-time usage of network resources corresponding to a particular radio access network and capacity of the particular radio access network, each loading coefficient being multiplied by a preference weighting element indicating a preferred service application of a service provider.

10. An apparatus of claim 9 , wherein the selection logic is further configured to determine whether one of the candidates supports a requested application service of the terminal, and to remove the one candidate from the list if the one candidate does not support the requested application service.

11. An apparatus of claim 9 , wherein the selection logic is further configured to determine a handover interruption time for one of the candidates, to compare the determined handover interruption time with a predetermined threshold value, and to remove the one candidate from the list if the determined handover interruption time satisfies a predetermined threshold value.

12. An apparatus of claim 9 , wherein the selection logic is further configured to determine a quality of service (QoS) parameter value for one of the candidates, and to remove one of the candidates from the list if the QoS parameter does not satisfy a predetermined QoS parameter value.

13. An apparatus of claim 9 , wherein the selection logic is further configured to retrieve a service policy corresponding to the terminal, and to remove one of the candidates from the list based on the service policy.

14. An apparatus of claim 9 , wherein the selection logic is further configured to receive a measurement report associated with one of the candidates, and to remove the one candidate from the list based on the measurement report.

15. An apparatus of claim 9 , further comprising:

a communication interface configured to obtain over-the-air measurements relating to loading of the radio access networks, or to communicate with one or more of the radio access networks to obtain the loading information.

16. An apparatus of claim 9 , further comprising: logic configured to perform a handover to one of the candidates.

17. A method comprising:

establishing communications with a plurality of radio access networks exhibiting, respectively, a plurality of radio access technologies;

generating, based on one or more predefined criterions, a list of candidate radio access networks from the plurality of radio access networks that are accessible to a terminal;

determining a universal loading indicator corresponding to the list of candidate radio access networks; and

selecting a target radio access network from the list of candidate radio access networks at least based on the universal loading indicator, wherein communications associated with the terminal are handed over to the target radio access network,

wherein the universal loading indicator includes a plurality of loading coefficients, each loading coefficient defining a ratio between real-time usage of network resources corresponding to a particular radio access network and capacity of the particular radio access network, each loading coefficient being multiplied by a preference weighting element indicating a preferred service application of a service provider.