RF Chain Usage in a Dual Network Architecture

1. A mobile device, comprising: a 3rd Generation Partnership Project (3GPP) long term evolution (LTE) baseband circuitry; a 2nd Generation (2G) or 3rd Generation (3G) baseband circuitry; and a radio frequency (RE) chain selectively switchable between the LTE baseband circuitry and the 2G or 3G baseband circuitry, wherein the RE chain is arranged to transmit at least a radio frame including a scheduling request (SR) provided in a physical uplink control channel (PUCCH) or to initiate a Random Access procedure to an evolved node B (eNodeB) associated with a LTE network and the RF chain is further arranged to transmit, over a frequency band and in response to the SR in the PUCCH or the Random Access procedure, an Activation/Deactivation request medium access control (MAC) control element (CE) wherein the Activation/Deactivation MAC CE comprises an instruction to deactivate a secondary cell included in the LTE network when the frequency band is the same as a frequency band supported by a 2G or 3G network, wherein the secondary cell comprises a component carrier, configured for the mobile device, different from a primary component carrier of a primary cell configured for the mobile device and both the primary and secondary cells are part of the LTE network.

2. The mobile device of claim 1 , wherein the Activation/Deactivation request MAC CE is provided in response to a voice call to be started supported by the 2G or 3G baseband circuitry coupled to the RF chain.

3. The mobile device of claim 2 , wherein the voice call comprises a mobile originating (MO) voice call or a mobile terminating (MT) voice call.

4. The mobile device of claim 1 , wherein the RE chain is further arranged to transmit the radio frame including the SR when a dedicated SR resource has been allocated by the eNodeB for the mobile device.

5. The mobile device of claim 1 , wherein the mobile device initiates the Random Access procedure when no dedicated SR resource has been allocated by the eNodeB for the mobile device.

6. The mobile device of claim 1 , wherein the mobile device receives physical uplink shared channel (PUSCH) resource scheduled by the eNodeB.

7. The mobile device of claim 6 , wherein the mobile device sends the Activation/Deactivation request MAC CE in the PUSCH resource scheduled by the eNodeB.

8. The mobile device of claim 1 , wherein the mobile device transmits an Activation/Deactivation MAC CE signaling to the eNodeB in response to the Activation/Deactivation request MAC CE provided by the mobile device.

9. The mobile device of claim 8 , wherein the Activation/Deactivation request MAC CE comprises identification of a cell to be activated or deactivated.

10. The mobile device of claim 1 , wherein the LTE network operates in time division duplexing (TDD) mode or frequency division duplexing (FDD) mode.