Re: stds-802-mobility: Hand-off question
All,
First,it is well known that the handoff include commonly:
1) Within MBWA
-- Inter-cell
-- Inter-sector
-- Inter-carrier
if MBWA does not support handoff within MBWA, then it is essentially a hot-spot application.
As such, what will be the usage cases where it delivers better customer experience than 802.11? the rather that 802.20 is a MAN! So, the handoff within MBWA system must be supported!
2) Inter-technology
-- WLAN
-- 3G
-- GSM,etc.
We know,802.20 is not a complementarity to 3g but a competitor or a replacer! Because it is MAN, not a WLAN such as 802.11.
If 802.20 is a complementarity to 3G or existing technology, we should not hesitate to consider supporting handoff between MBWA and 3G. Is it? No, It isn't!
Here note that we should not hesitate to consider supporting communication between 802.20 and 3G.
Second, we can discuss the handoff among technologies from implementary mode, we know the handoff mode
1) Network-controlled handoff
2) Mobile-controlled handoff
If adopt the first mode,
-- it need have distinct mobility controller and base stations creates artificial separation between handoffs and other PHY/MAC/LLC activities.
-- Does not fit well with IETF decentralized mobility mgmt protocols such as Mobile IP
-- Limitations on scalability and flexibility
Furthermore, I think that the handoff among technologies adopting network-controlled mode is not feasible. we assume that
3G network belongs to Vendor A, and 802.20 MBWA network belongs to Vendor B, when a Mobile may handoff between the two networks, Vendor A and Vendor B all hope certainly the Mobile still stay at own network.
If adopt the second mode, I think the Mobile will become very expensive.
Best Regards,
Wujianjun--Huawei