Handoff detection method, for SimpleIP and MobileIP, which supports IOS 40 and which allows inter-PCF handoff while maintaining connectivity as well as Inter-PDSN handoff even when going back to source PDSN and reusing existing RP session
Publication Date: 2001-Jan-24
The IP.com Prior Art Database
Jerome Duplaix: AUTHOR [+4]
The idea is to obtain, during the PPP negotiation, a Magic Number identifying the MN. With that Magic Number being kept into its bindings, the PDSN would trigger the exchange of Echo messages when an A11-RRQ is received, without any Vendor Specific Extension or with only the Active Start attribute, or when an A11-RRQ with connection setup attribute is received for a MN already registered. If the Magic Number specified within the Echo message is not the one expected by the PDSN (kept into the binding), the PPP session must be re-negotiated (the MN is coming from another PDSN).
This defensive publication is made by Ericsson Communications Canada in order to put in the public domain the present subject-matter, and thus to prevent others from patenting it, as well as any other related subject-matter that would be obvious in view of the present publication, in any national jurisdiction.
1 Name of invention
Handoff detection method, for SimpleIP and MobileIP, which supports IOS 4.0 and which allows inter-PCF handoff, while maintaining connectivity, as well as Inter-PDSN handoff, even when going back to the source PDSN and re-using existing R-P session.
2 Authors (from Ericsson Communications Canada)
Jerome Duplaix, Michelle Perras, Louis Segura
This invention relates to CDMA2000 packet data standard (IS-835) which defines the requirements to support wireless packet data networking capabilities on a third generation wireless system.
This invention relates to the Simple IP &Mobile IP services defined into the IS-835.
SimpleIP service enables a Mobile Node(MN) to register with a PDSN in order to acquire access to a packet data network. The MN connects to a PCF, via wireless access. The PCF then connects to a PDSN. An R-P session is used between the PCF and the PDSN. Once this session is established, the PDSN and the MN must negotiate a PPP session. The PDSN allocates a local IP address to the MN during the PPP negotiation.
The same mechanism is used for MobileIP service but instead of having an IP address allocated locally by the PDSN, the MN already has an IP address statically configured, or obtains one from its Home Agent (HA) through the exchange of MIP Registration request/reply messages.
When using SimpleIP or MobileIP services, a Mobile Node may roam to the coverage of another PCF, which is either connected to the same PDSN or to another PDSN.
The IS-835 defines that when an inter-PCF handoff occurs (same PDSN), a new R-P session should be established with the target PCF while maintaining PPP session and IP address (maintaining connectivity). This applies to both SIP MIP.
For inter-PDSN handoff, a new R-P session should be established (if none exists for the specific MN) and the PPP session must be negotiated. This is required for SIP in order to re-allocate a topologically correct IP address form the target PDSN. For MIP, it is required in order for the MN to re-register a valid Care-Of-Address(COA), obtained from the target PDSN, with its HA.
In order to support the handoffs as described above, the IS-835 specifies that the Ingress Filtering functionality should be used in order to determine when to start the PPP (re)negotiation.
Using the Ingress Filtering in order to trigger the PPP negotiation is not adequate for the following reasons:
The MN has to send data in order to be able to use the Ingress Filtering and trigger the PPP negotiation. The MN ...