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 mobile communications device having a processor and software executable by the processor, further configurable for having a protocol stack stored in a memory, the protocol stack having a first access stratum, a second access stratum, and a non-access stratum, and where the mobile communication device also has a communication sub-system operable to communicate with a plurality of core-network-connected wireless access networks, the processor in combination with the software configurable to cause:
providing an interface between the non-access stratum with the first access stratum and with the second access stratum;
activating the first access stratum to establish a communication link with a core-network over a first core-network-connected wireless access network;
transferring control of the communication link to the second access stratum; and
maintaining the communication link between the non-access stratum and the core-network while transferring control of the communication link to the second access stratum.
2. The device of claim 1 further configurable to measure respective signal strengths of the first wireless access network and a second wireless access network of the plurality of wireless access networks.
3. The device of claim 2 where the transferring control of the communication link is a function of the measurements made of the respective signal strengths.
4. The device of claim 3 further configurable to generate a handover control signal by the first access stratum responsive to the measured signal strengths, and configurable to transfer control of the communication link responsive to generation of the handover control signal.