Method and system for determining access during inter-technologies handoff
A system and method for determining an initial mean open loop power level of a pilot channel of a reverse traffic channel for a mobile terminal. The initial open loop power level enables handoff of an active call from a first access network to a second access network. A handoff initialization request is from the first access network. A mean received power level of the forward link of the second access network is measured and transmitted to the second access network. An open loop power adjustment factor is received from the second access network. The initial mean open loop power level is set based on the open loop power adjustment factor.
1. A method for determining an initial mean open loop power level of a pilot channel of a reverse traffic channel for a mobile terminal, the initial open loop power level enabling handoff of an active call from a first access network to a second access network, the method comprising:
receiving a handoff initialization request from the first access network;
measuring a mean received power level of the forward link of the second access network, wherein the second access network and the first access network comprise different radio access technologies (RATs);
transmitting the measured mean forward link power to the second access network;
receiving an open loop power adjustment factor from the second access network; and
setting the initial mean open loop power level based on the open loop power adjustment factor.
2. The method of claim 1 , wherein the open loop power adjustment factor is based on the measured mean forward link power.
3. The method of claim 1 , wherein the initial mean open loop power level is further based on a mean output power of a pilot channel at termination of a prior reverse traffic channel transmission and a difference between a mean forward link power at termination of the prior reverse traffic channel transmission and the measured mean forward link power.
4. The method of claim 1 , wherein the initial mean open loop power level is further based on an initial power level less the measured mean forward link power.
5. The method of claim 4 , wherein the initial power level is received from the second access network.
6. The method of claim 4 , wherein the mobile terminal includes a memory, the initial power level being stored in the memory.
7. The method of claim 1 , wherein the measured mean forward link power is transmitted to the second access network through a tunneling interface.
8. The method of claim 1 , wherein the first access network comprises Long Term Evolution and the second access network comprises CDMA2000.
9. The method of claim 1 , further comprising transmitting data to the second access network using the reverse traffic channel.
10. The method of claim 1 , further comprising preventing transmission of data to the second access network on the reverse traffic channel for a pre-determined delay time, the pre-determined delay time being sufficient to permit the second access network and the mobile terminal to adjust the power level of the reverse traffic channel.
11. A system for determining an initial mean open loop power level of a pilot channel of a reverse traffic channel for a mobile terminal, the initial open loop power level enabling handoff of an active call between at least two different wireless access networks, the system comprising:
a first wireless access network comprising a first radio access technology (RAT), the first wireless access network operable to transmit a handoff initialization request to the mobile terminal, wherein the handoff initialization request instructs the mobile terminal to handoff from the first wireless access network to a second wireless access network; and
the second wireless access network having comprising a second RAT, wherein the second RAT is different than the first RAT, the second wireless access network operable to:
receive a measured mean forward link power of the second wireless access network; determine an open loop power adjustment factor; and transmit the open loop power adjustment factor to the mobile terminal.
12. The system of claim 11 , wherein the mobile terminal is operable to set the initial mean open loop power level based on the open loop power adjustment factor.
13. The system of claim 12 , wherein the initial mean open loop power level is further based on a mean output power of a pilot channel at termination of a prior reverse traffic channel transmission, and a difference between a mean forward link power at termination of the prior reverse traffic channel transmission and the measured mean forward link power.
14. The system of claim 12 , wherein the initial mean open loop power level is further based on an initial power level less the measured mean forward link power.
15. The system of claim 14 , wherein second wireless access network is further operable to transmit the initial power level.
16. The system of claim 14 , wherein the mobile terminal includes a memory, the initial power level being stored in the memory.
17. The system of claim 11 , wherein first wireless access network further includes a tunneling module, the first wireless access network is further operable to transmit the measured mean forward link power to the second wireless access network through a tunneling interface.
18. The system of claim 11 , wherein the first wireless access network comprises Long Term Evolution and the second wireless access network comprises CDMA2000.
19. The system of claim 11 , wherein the mobile terminal is further operable to transmit data to the second wireless access network using the reverse traffic channel.
20. The system of claim 11 , wherein the mobile terminal is further operable to prevent transmission of data to the second wireless access network on the reverse traffic channel for a pre-determined delay time, the pre-determined delay time being sufficient to permit the second wireless access network and the mobile terminal to adjust the power level of the reverse traffic channel.