Access stratum manager
View Patent ↗A multi-mode mobile communication device may include a processing device, a memory sub-system, a communication sub-system operable to communicate with the plurality of wireless access networks, and a protocol stack stored in the memory sub-system and executed by the processing device. The protocol stack may include a first access stratum, a second access stratum, a non-access stratum and an access stratum manager. The first access stratum may communicate with a first wireless access network via the communication sub-system. The second access stratum may communicate with a second wireless access network via the communication sub-system. The non-access stratum may communicate with a core network. The access stratum manager may interface the non-access stratum with the first and second access strata, and may be operable to activate the first access stratum to establish a communication link with the core network over the first wireless access network. The access stratum manager may be further operable to maintain the communication link between the non-access stratum and the core network while transferring the communication link from the first access stratum to the second access stratum.
1. A method for managing communications at a multi-mode mobile communication device having a protocol stack stored at a memory sub-system thereof, and the multi-mode mobile communication device also having a communication sub-system operable to communicate with a plurality of core-network connected wireless access networks, said method comprising the operations of:
interfacing a non-access stratum of the protocol stack with a first access stratum and a second access stratum;
activating the first access stratum to establish a communication link between the non-access stratum and a core network over a first core-network-connected wireless access network of the plurality of wireless access networks;
transferring control of the communication link, established during said operation of activating the first access stratum to establish the communication link, from the first access stratum to the second access stratum;
maintaining the communication link between the non-access stratum and the core network while transferring, during said operation of transferring the control of the communication link to the second access stratum.
2. The method of claim 1 further comprising an operation of measuring respective signal strengths of the first wireless access network and a second wireless access network of the plurality of wireless access networks.
3. The method of claim 2 wherein said operation of transferring control of the communication link is performed responsive to measurements made during said operation of measuring the respective signal strengths.
4. The method of claim 3 further comprising an operation of generating a handover control signal by the first access stratum responsive to measured signal strengths measured during said operation of measuring and wherein said operation of transferring control of the communication link is performed responsive to generation of the handover control signal.
5. Apparatus for managing communications at a multi-mode mobile communication device having a protocol stack stored at a memory sub-system thereof, the protocol stack having a first access stratum, a second access stratum, and a non-access stratum and the multi-mode mobile communication device also having a communication sub-system operable to communicate with a plurality of core-network connected wireless access networks, said apparatus comprising:
means for interfacing the non-access stratum with the first access stratum and with the second access stratum;
means for activating the first access stratum to establish a communication link with a core network over a first core-network-connected wireless access network of the plurality of wireless access networks;
means for transferring control of the communication link, established by said means for activating the first access stratum to establish the communication link, from the first access stratum to the second access stratum; and
means for maintaining the communication link between the non-access stratum and the core network while transferring, by said means for transferring the control of the communication link to the second access stratum.
6. The apparatus of claim 5 further comprising means for measuring respective signal strengths of the first wireless access network and a second wireless access network of the plurality of wireless access networks.
7. The apparatus of claim 6 wherein said means for transferring control of the communication link transfers control of the communication link responsive to measurements made by said means for measuring the respective signal strengths.
8. The apparatus of claim 6 further comprising means for generating a handover control signal by the first access stratum responsive to measured signal strengths measured by said means for measuring and wherein said means for transferring control of the communication link is configured to transfer control responsive to generation of the handover control signal.