US6763007B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Two phase local mobility scheme for wireless access to packet based networks
Assignee: RPX Corp
•
Filing: 1998-12-11
•
Granted: 2004-07-13
•
Expires: 2018-12-11
Abstract
Abstract Local mobility within a subnet is supported by classifying wireless base stations, and the routers used to forward packets to those base stations, within defined domains. Domains are defined to incorporate a subnet having a plurality of base stations. Base stations are used by mobile devices to attach to the wired portion of a packet-based network, such as the Internet, and exchange packets thereover with a correspondent node. Packets sent from the correspondent node to the mobile device have a packet destination address corresponding to the mobile device. The mobile device retains this address for the duration of time it is powered up and attached to the Internet via any base station within a given domain. Host-based routing is utilized to update routing table entries corresponding to the mobile device at routers incorporated within a single domain. The routing table entries are established and updated via path setup schemes to convey packets destined for the mobile device along the proper established path through the domain routers and base stations, regardless of the domain base station through which the mobile device is attached. Path setup schemes utilize power up, refresh, and handoff path setup messages to maintain the proper relationship between router interfaces and packet addresses for routing table entries.
Inventors
- 👤 Thomas F. La Porta
- 👤 Kazutaka Murakami
- 👤 Ramachandran Ramjee
- 👤 Sandra R. Thuel
- 👤 Kannan Varadhan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 03:49
CPC Classifications
H; H04; H04W; H04W8/00; H04W8/02; H04W8/08; H04W8/082; H04L; H04L45/00; H04L45/02; H04W8/087; H04W80/00; H04W80/04
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
259 words
A method of establishing a routing path for packet delivery to a destination node within a packet-based subnet, said destination node having a destination node address, said method comprising the steps of: launching a path setup message from said destination node; receiving said path setup message over a first interface at a first router; and creating a first routing table entry for a first routing table, said first routing table entry associating a second interface and said destination node address with said first interface, wherein a packet, subsequently received over said second interface and having said destination node address as a packet header destination address, is forwarded from said first router over said first interface after said first router associates said second interface and said destination node address with said first routing table entry, and wherein said first router is incorporated within a first wireless base station, further including forwarding a handoff path setup message, for handoffs processed at a network layer, from a second wireless base station to said first wireless base station if said wireless device is handed off from said first wireless base station to said second wireless base station, said handoff update path setup message used to alter routing table entries for a plurality of subnet routers and further comprising the step of maintaining said first routing table entry as a soft state in said first router, said first routing table entry overwritten with a default entry if a refresh path setup message is not received at said router within a specified period of time.
Claim 2
Independent Claim
259 words
A method of establishing a routing path for packet delivery to a destination node within a packet-based subnet, said destination node having a destination node address, said method comprising the steps of: launching a path setup message from said destination node; receiving said path setup message over a first interface at a first router; and creating a first routing table entry for a first routing table, said first routing table entry associating a second interface and said destination node address with said first interface, wherein a packet, subsequently received over said second interface and having said destination node address as a packet header destination address, is forwarded from said first router over said first interface after said first router associates said second interface and said destination node address with said first routing table entry, and wherein said first router is incorporated within a first wireless base station, further including forwarding a handoff path setup message, for handoffs processed at a network layer, from a second wireless base station to said first wireless base station if said wireless device is handed off from said first wireless base station to said second wireless base station, said handoff update path setup message used to alter routing table entries for a plurality of subnet routers and further comprising the step of maintaining said first routing table entry as a soft state in said first router, said first routing table entry overwritten with a default entry if a refresh path setup message is not received at said router within a specified period of time.
Claim 3
Dependent Claim
15 words
The method in accordance with claim 1 wherein said destination node is a wireless device.
Claim 4
Dependent Claim
15 words
The method in accordance with claim 2 wherein said wireless device is a TDMA device.
Claim 5
Dependent Claim
19 words
The method in accordance with claim 1 wherein said first router is incorporated within a first wireless base station.
Claim 6
Dependent Claim
16 words
The method in accordance with claim 1 wherein said packet-based subnet is an Internet Protocol subnet.
Claim 7
Independent Claim
261 words
A method of establishing a routing path for packet delivery to a destination node within a packet-based subnet, said destination node having a destination node address, said method comprising the steps of: launching a path setup message from said destination node; receiving said path setup message over a first interface at a first router; and creating a first routing table entry for a first routing table, said first routing table entry associating a second interface and said destination node address with said first interface, wherein a packet, subsequently received over said second interface and having said destination node address as a packet header destination address, is forwarded from said first router over said first interface after said first router associates said second interface and said destination node address with said first routing table entry, and wherein said first router is incorporated within a first wireless base station, further including forwarding a handoff path setup message, for handoffs processed at a network layer, from a second wireless base station to said first wireless base station if said wireless device is handed off from said first wireless base station to said second wireless base station, said handoff update path setup message used to alter routing table entries for a plurality of subnet routers, and wherein during a first handoff phase, data packets continue to arrive at an old base station and are then forwarded from the old base station to a new base station, and during a second handoff phase, a dynamically determined cross-over router forwards the packets to the new base station.
Claim 8
Independent Claim
261 words
A method of establishing a routing path for packet delivery to a destination node within a packet-based subnet, said destination node having a destination node address, said method comprising the steps of: launching a path setup message from said destination node; receiving said path setup message over a first interface at a first router; and creating a first routing table entry for a first routing table, said first routing table entry associating a second interface and said destination node address with said first interface, wherein a packet, subsequently received over said second interface and having said destination node address as a packet header destination address, is forwarded from said first router over said first interface after said first router associates said second interface and said destination node address with said first routing table entry, and wherein said first router is incorporated within a first wireless base station, further including forwarding a handoff path setup message, for handoffs processed at a network layer, from a second wireless base station to said first wireless base station if said wireless device is handed off from said first wireless base station to said second wireless base station, said handoff update path setup message used to alter routing table entries for a plurality of subnet routers, and wherein during a first handoff phase, data packets continue to arrive at an old base station and are then forwarded from the old base station to a new base station, and during a second handoff phase, a dynamically determined cross-over router forwards the packets to the new base station.
Claim 9
Dependent Claim
27 words
The method in accordance with claim 6 wherein said plurality of subnet routers include at least said first wireless base station and said second wireless base station.
Claim 10
Dependent Claim
19 words
The method in accordance with claim 6 wherein said handoff path setup message is initiated from said wireless device.
Claim 11
Independent Claim
207 words
A method for forwarding a received packet from a router, said method comprising the steps of: forwarding said received packet over a first interface if said received packet includes a first packet header destination address and was received over a second interface; and forwarding said received packet over a third interface if said received packet includes said first packet header destination address and was received over an interface other than said second interface, wherein said router is incorporated within a first wireless base station, further including forwarding a handoff path setup message, for handoffs processed at a network layer, from a second wireless base station to said first wireless base station if said wireless device is handed off from said first wireless base station to said second wireless base station, said handoff update path setup message used to alter routing table entries for a plurality of subnet routers, wherein said forwarding is performed in response to a lookup of a routing table entry in said routing table, said routing table entry including said first packet header destination address as a first field value and an interface over which said received packet arrives at said router as an ingress interface field value, and an egress interface field value.
Claim 12
Independent Claim
207 words
A method for forwarding a received packet from a router, said method comprising the steps of: forwarding said received packet over a first interface if said received packet includes a first packet header destination address and was received over a second interface; and forwarding said received packet over a third interface if said received packet includes said first packet header destination address and was received over an interface other than said second interface, wherein said router is incorporated within a first wireless base station, further including forwarding a handoff path setup message, for handoffs processed at a network layer, from a second wireless base station to said first wireless base station if said wireless device is handed off from said first wireless base station to said second wireless base station, said handoff update path setup message used to alter routing table entries for a plurality of subnet routers, wherein said forwarding is performed in response to a lookup of a routing table entry in said routing table, said routing table entry including said first packet header destination address as a first field value and an interface over which said received packet arrives at said router as an ingress interface field value, and an egress interface field value.
Claim 13
Dependent Claim
17 words
The method in accordance with claim 9 wherein said second and third interfaces are the same interface.
Claim 14
Dependent Claim
24 words
The method in accordance with claim 9 wherein said routing table entry is formed in response to receiving a power up path setup message.
Claim 15
Dependent Claim
27 words
The method in accordance with claim 9 wherein said routing table entry is maintained as a valid entry in response to receiving a refresh path setup message.
Claim 16
Dependent Claim
15 words
The method in accordance with claim 12 wherein said router is a soft state router.
Claim 17
Dependent Claim
17 words
The method in accordance with claim 9 wherein said router is incorporated within a wireless base station.
Claim 18
Dependent Claim
17 words
The method in accordance with claim 9 wherein said wireless base station is a TDMA base station.
Claim 19
Dependent Claim
17 words
The method in accordance with claim 9 wherein said router is an Internet Protocol (IP) packet router.
Claim 20
Independent Claim
166 words
A method for forwarding a received packet from a router, said method comprising the steps of: forwarding said received packet over a first interface if said received packet includes a first packet header destination address and was received over a second interface; forwarding said received packet over a third interface if said received packet includes said first packet header destination address and was received over an interface other than said second interface, wherein said router is incorporated within a first wireless base station, further including forwarding a handoff path setup message, for handoffs processed at a network layer, from a second wireless base station to said first wireless base station if said wireless device is handed off from said first wireless base station to said second wireless base station, said handoff update path setup message used to alter routing table entries for a plurality of subnet routers, and utilizing a dynamically determined cross-over router to forward packets to a new base station during a handoff process.
Claim 21
Independent Claim
166 words
A method for forwarding a received packet from a router, said method comprising the steps of: forwarding said received packet over a first interface if said received packet includes a first packet header destination address and was received over a second interface; forwarding said received packet over a third interface if said received packet includes said first packet header destination address and was received over an interface other than said second interface, wherein said router is incorporated within a first wireless base station, further including forwarding a handoff path setup message, for handoffs processed at a network layer, from a second wireless base station to said first wireless base station if said wireless device is handed off from said first wireless base station to said second wireless base station, said handoff update path setup message used to alter routing table entries for a plurality of subnet routers, and utilizing a dynamically determined cross-over router to forward packets to a new base station during a handoff process.
Claim 22
Independent Claim
187 words
A method for forwarding a received packet from a router, said method comprising the steps of: forwarding said received packet over a first interface if said received packet includes a first packet header destination address and was received over a second interface; and forwarding said received packet over a third interface if said received packet includes said first packet header destination address and was received over an interface other than said second interface, wherein said router is incorporated within a first wireless base station, further including forwarding a handoff path setup message, for handoffs processed at a network layer, from a second wireless base station to said first wireless base station if said wireless device is handed off from said first wireless base station to said second wireless base station, said handoff update path setup message used to alter routing table entries for a plurality of subnet routers, and further including the step of maintaining said routing table entries as a soft state, said routing table entries overwritten with a default entry if a refresh path setup message is not received within a specified period of time.
Claim 23
Independent Claim
187 words
A method for forwarding a received packet from a router, said method comprising the steps of: forwarding said received packet over a first interface if said received packet includes a first packet header destination address and was received over a second interface; and forwarding said received packet over a third interface if said received packet includes said first packet header destination address and was received over an interface other than said second interface, wherein said router is incorporated within a first wireless base station, further including forwarding a handoff path setup message, for handoffs processed at a network layer, from a second wireless base station to said first wireless base station if said wireless device is handed off from said first wireless base station to said second wireless base station, said handoff update path setup message used to alter routing table entries for a plurality of subnet routers, and further including the step of maintaining said routing table entries as a soft state, said routing table entries overwritten with a default entry if a refresh path setup message is not received within a specified period of time.
References Cited (Backward Citations)
US5159592A
Cited
EP0483547A1
Cited
US5717688A
Cited
US5564070A
Cited
US5325362A
Cited
US5519706A
Cited
US5812531A
Cited
US5598536A
Cited
US5533026A
Cited
US5812819A
Cited
EP0768806A2
Cited
US5790548A
Cited
US6243758B1
Cited
US5708655A
Cited
US6122268A
Cited
US6181935B1
Cited
US6141325A
Cited
US6442616B1
Cited
US6473411B1
Cited
US6272148B1
Cited
US6230013B1
Cited
US6484211B2
Cited
US6407988B1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2007-07-13 | 2008-01-12 | 2008-07-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2011-07-13 | 2012-01-12 | 2012-07-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2015-07-13 | 2016-01-12 | 2016-07-13 | $7700.00 | Window Closed / Lapsed |