Providing a mobility state for a mobile device

1. A method comprising:

performing a procedure to transition a mobile device from a first wireless access network to a second wireless access network; and

in response to the transition, applying a mapping to obtain a particular mobility state of the mobile device to use in the second wireless access network, wherein the mapping outputs the particular mobility state to use in the second wireless access network in response to information associated with mobility of the mobile device in the first wireless access network, the mapping correlating a first collection of mobility states for a first access technology of the first wireless access network to a second collection of mobility states for a second, different access technology of the second wireless access network.

2. The method of claim 1 , wherein applying the mapping comprises accessing a mapping data structure that correlates the first collection of mobility states for the first access technology of the first wireless access network to the second, different collection of mobility states for the second, different access technology of the second wireless access network.

3. The method of claim 2 , wherein the mapping data structure has a plurality of entries, wherein each of the plurality of entries correlates a corresponding mobility state of the first collection to a corresponding mobility state of the second collection.

4. The method of claim 1 , wherein the first collection of mobility states is for a Universal Terrestrial Radio Access Network (UTRAN), and the second, different collection of mobility states is for an Evolved UTRAN.

5. The method of claim 1 , wherein the first collection of mobility states is for an Evolved Universal Terrestrial Radio Access Network (EUTRAN), and the second, different collection of mobility states is for a UTRAN.

6. The method of claim 1 , wherein applying the mapping comprises applying a function that produces the particular mobility state in response to the information associated with mobility of the mobile device in the first wireless access network.

7. The method of claim 6 , wherein the function produces the particular mobility state in response to information indicating a cell change rate of the mobile device in at least the first wireless access network.

8. The method of claim 7 , wherein the cell change rate of the mobile device in the first wireless access network is based on a number of transitions among cells performed by the mobile device in at least the first wireless access network in a predefined time window.

9. The method of claim 8 , wherein the cell change rate of the mobile device is further based on a predetermined time interval used for defining a mobility state of the mobile device in the second wireless access network.

10. The method of claim 1 , wherein the performing and applying are performed at a network node including a processor, the method further comprising:

receiving, at the network node from the mobile device, the information associated with mobility of the mobile device in the first wireless access network.

11. The method of claim 1 , further comprising:

storing, in the mobile device, information relating to a mobility state of the mobile device in the first wireless access network prior to transitioning the mobile device from the first wireless access network to the second wireless access network; and

using the stored information to obtain a mobility state for the mobile device when the mobile device transitions back to the first wireless access network.

12. The method of claim 1 , wherein the performing and applying are performed at the mobile device, the method further comprising:

receiving, at the mobile device, information relating to the mapping from a network node of the second wireless access network.

13. A method comprising:

receiving, by a first device from a second device, information relating to a mobility state of a mobile device, wherein the mobility state is based on mobility of the mobile device in a first wireless access network, the information relating to the mobility state received in a handover message relating to handing over the mobile device from the first wireless access network to a second wireless access network,

wherein the first device is one of the mobile device and a network node in communication with the mobile device, and the second device is the other of the mobile device and the network node; and

applying, by the first device, a mapping to determine a mobility state of the mobile device to use in the second wireless access network, based on the received information relating to the mobility state of the mobile device in the first wireless access network, the mapping correlating a first collection of mobility states for a first access technology of the first wireless access network to a second collection of mobility states for a second, different access technology of the second wireless access network.

14. The method of claim 13 , wherein the mobility state is based on a rate of transitioning between cells by the mobile device.

15. The method of claim 13 , wherein the mobility state is based on a velocity of the mobile device.

16. The method of claim 13 , wherein the handover message includes one of a HANDOVER FROM UTRAN command message and a HANDOVER TO UTRAN COMPLETE message.

17. A system comprising:

an interface to communicate over a network; and

at least one processor configured to:

detect a type of transition by a mobile device between cells; and

identify a set of mobility state parameters from a plurality of sets of mobility state parameters based on the detected type of transition, wherein the identified set of mobility state parameters is useable to determine a mobility state of the mobile device after the transition, the identifying comprising:

identifying a first set of the plurality of sets of mobility state parameters based on detecting an intra-access technology transition between cells of a same access technology; and

identifying a second, different set of the plurality of sets of mobility state parameters based on detecting an inter-access technology transition between cells of different access technologies.

18. The system of claim 17 , wherein detecting the type of transition comprises detecting the inter-access technology transition between a first wireless access network according to a first access technology, and a second wireless access network according to a second, different access technology.

19. The system of claim 17 , wherein the identified set of mobility parameters includes a number parameter and a time interval parameter, wherein the number parameter represents a number of cell changes, and the time interval parameter represents a predefined time interval during which the number of cell changes is counted.

20. The system of claim 17 , wherein the system is one of the mobile device and a network node.

21. A system comprising:

an interface to communicate over a network; and

at least one processor configured to:

perform a procedure to transition a mobile device from a first wireless access network to a second wireless access network; and

in response to the transition, apply a mapping to obtain a particular mobility state of the mobile device to use in the second wireless access network, wherein the mapping outputs the particular mobility state to use in the second wireless access network in response to information associated with mobility of the mobile device in the first wireless access network, the mapping correlating a first collection of mobility states for a first access technology of the first wireless access network to a second collection of mobility states for a second, different access technology of the second wireless access network.

22. The system of claim 21 , wherein the system is one of the mobile device and a network node.