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Selective Error protection for time-sensitive inter-access router signaling over UDP

IP.com Disclosure Number: IPCOM000010766D
Original Publication Date: 2003-Jan-16
Included in the Prior Art Database: 2003-Jan-16
Document File: 7 page(s) / 128K

Publishing Venue

Motorola

Related People

Madjid Nakhjiri: AUTHOR

Abstract

This paper is providing a new application level reliability mechanisms for time sensitive lightweight signaling between nodes at the edge of an access network. Such signaling may carry sub payloads with varying degree of reliability and hence cannot easily employ a traditional reliable transport protocol such as TCP. The reliability mechanism described in this paper, provides a large degree of flexibility in the degree of reliability. Correct sub payloads can be extracted from the packet, while allowing retransmission requests (the number of retransmissions can be pre-determined for each sub payload type). Also in cases the originally retransmitted data is no longer valid, updates can be requested as well.

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Selective Error protection for time-sensitive inter-access router signaling over UDP

Madjid Nakhjiri

Abstract

This paper is providing a new application level reliability mechanisms for time sensitive lightweight signaling between nodes at the edge of an access network. Such signaling may carry sub payloads with varying degree of reliability and hence cannot easily employ a traditional reliable transport protocol such as TCP. The reliability mechanism described in this paper, provides a large degree of flexibility in the degree of reliability. Correct sub payloads can be extracted from the packet, while allowing retransmission requests (the number of retransmissions can be pre-determined for each sub payload type). Also in cases the originally retransmitted data is no longer valid, updates can be requested as well.

1.   Background and Problem statement

In mobile access networks, i.e. network providing access to mobile node (MN) users, special routers called access routers (AR) that need to provide more sophisticated services than traditional network routers are deployed. From the mobile node’s user trying to access the network, the AR is the first hop router that not only provides IP layer routing (tradition router), but also enables roaming to other subnets. This implies that, in order to provide seamless service offering, the AR needs to support mechanisms accommodating routing changes (such as Mobile IP functionality [1-2]) as well as administrative and service provisioning features such as handover authentication, QoS and header compression re-establishment and so on. A new mechanism called Context Transfer (referred to as CT in this paper) being developed in IETF [3-5] that prevents the need for MN-newAR signaling for re-establishment these service-enhancing features by transferring the feature states that exist at the oldAR for the MN to the newAR. The CT protocol allows the MN to avoid having to re-negotiate its service features with the new AR after performing a handover and thereby, wasting both precious air-link bandwidth and handover time on these re-negotiation.

During the process of context transfer (CT) one access router will send all its states pertaining to a mobile user to another access router to optimize a network level handover. States belonging to different protocols will be conveyed as sub payloads to a context transfer packet (including CT header, Message header and CT payload).

Regardless of the degree of control the MN imposes on the handover and service establishment signaling, experience has shown that some amount of signaling needs to occur at network level (bypassing the MN) to make the handover more bandwidth and delay efficient. Depending on whether the ARs on both side of the handover scenario (oldAR and newAR) are part of the same administrative domain, some or all signaling will happen directly between the two ARs (as opposed to through central management entities).

Inter-AR Signaling in conjunction with hando...