Adaptive IP handoff triggering and iterative tuning of IP handoff trigger timing
View Patent ↗A method and system for providing an adaptive IP handoff triggering system for a wireless communication system that consists of either the same or heterogeneous wireless access technologies. A mobile node is notified of at least one pre-trigger timing parameter by a current access network. At least one variable handoff threshold is constructed with the mobile node based on the at least one pre-trigger timing parameter. An IP handoff is then initiated to a candidate access network when pilot beacon signal strength of the mobile node reaches the variable handoff threshold.
1. A method for providing an adaptive handoff triggering system for a wireless communication system, comprising the steps of: notifying a mobile node of a value of a pre-trigger timing parameter with a current access network, said pre-trigger timing parameter being related to an estimated time duration between a layer 3 handoff request and a corresponding link layer disconnection; constructing a variable handoff threshold with said mobile node based on said pre-trigger timing parameter; and initiating a handoff to a candidate access network when a pilot beacon signal strength on said mobile node reaches said variable handoff threshold.
2. The method of claim 1 , further comprising the step of reporting an IP blackout duration to said current access network.
3. The method of claim 2 , further comprising the step of retuning said pre-trigger timing parameter based on said blackout period.
4. The method of claim 3 , wherein an adaptive tuner is used to retune said pre-trigger timing parameter.
5. The method of claim 4 , wherein said adaptive tuner uses an adaptive algorithm to retune said pre-trigger timing parameter.
6. The method of claim 5 , wherein said adaptive algorithm comprises a least mean square algorithm.
7. The method of claim 1 , wherein said variable handoff threshold is above a signal link down threshold.
8. The method of claim 1 , wherein said variable handoff threshold is calculated based on a mathematical mapping equation.
9. The method of claim 8 , wherein said mathematical mapping equation is defined as
Th
adaptive
=
T
t
T
beacon
*
Δ
+
S
LD
.
10. A method of claim 1 , wherein the handoff is initiated by the current access network.
11. A method of claim 1 , wherein the handoff is initiated by the mobile node.
12. An adaptive handoff triggering system for a wireless access network, comprising: an active access network; and a mobile node connected to said active access network, wherein said mobile node is provided with at least one pre-trigger timing parameter by said active access network, said pre-trigger timing parameter being related to an estimated time duration between a layer 3 handoff request and a corresponding link layer disconnection, wherein said mobile node constructs a variable handoff threshold based on said pre-trigger timing parameter; and wherein when said mobile node comes within a radio range of a candidate access network, a handoff is initiated to said candidate access network when a beacon pilot signal strength on said mobile node reaches said variable handoff threshold.
13. The adaptive handoff triggering system of claim 12 , wherein an IP blackout duration is reported to said active access network by said mobile node.
14. The adaptive handoff triggering system of claim 13 , wherein said pre-trigger timing parameter is retuned based on said blackout duration.
15. The adaptive handoff triggering system of claim 14 , wherein an adaptive tuner is used to retune said pre-trigger timing parameter.
16. The adaptive handoff triggering system of claim 15 , wherein said adaptive tuner uses an adaptive algorithm to retune said pre-trigger timing parameter.
17. The adaptive handoff triggering system of claim 16 , wherein said adaptive algorithm comprises a least mean square algorithm.
18. The adaptive handoff triggering system of claim 12 , wherein said variable handoff threshold is above a signal link down threshold.
19. The adaptive handoff triggering system of claim 12 , wherein said variable handoff threshold is calculated based on a mathematical mapping equation.
20. The adaptive handoff triggering system of claim 19 , wherein said mathematical mapping equation is defined as
Th
adaptive
=
T
t
T
beacon
*
Δ
+
S
LD
.
21. The adaptive handoff triggering system of claim 12 , wherein the handoff is initiated by the current access network.
22. The adaptive handoff triggering system of claim 12 , wherein the handoff is initiated by the mobile node.
23. A method for providing an adaptive handoff triggering system for a wireless communication system, comprising the steps of: transmitting a pre-trigger timing parameter to a mobile node, said pre-trigger timing parameter being related to an estimated time duration between a layer 3 handoff request and a corresponding link layer disconnection; measuring a beacon pilot signal strength between said mobile node and a current access network; and triggering a handoff to a candidate access network when said beacon pilot signal strength reaches a variable handoff threshold.
24. The method of claim 23 , wherein the handoff is initiated by the current access network.
25. A method for providing an adaptive handoff triggering system for a wireless communication system, comprising the steps of: notifying a mobile node of a pre-trigger timing parameter with a current access network, said pre-trigger timing parameter relating to an estimated time duration between a layer 3 handoff request and a corresponding link layer disconnection; constructing a variable handoff threshold in said mobile node based on said pre-trigger timing parameter; initiating a handoff to a candidate access network when a pilot beacon signal strength on said mobile node reaches said variable handoff threshold; reporting an IP blackout duration to said current access network; and retuning said pre-trigger timing parameter based on said blackout duration.
26. The method of claim 25 , wherein the handoff is initiated by the mobile node.
27. The method of claim 25 , wherein the handoff is initiated by the current access network.
28. The method of claim 25 , wherein the handoff is initiated by the mobile node.