US 2014/0369314 A1 · Method and Apparatus for Seamless Handover in a Wireless Communication Network

Abstract

In a wireless communication network where base stations receive protocol data units (PDUs) from mobile stations for decompression and deciphering for ordered, sequential transfer as service data units (SDUs) to an associated core network, the teachings presented herein provide a method of supporting seamless handover of a mobile station from a source base station to a target base station. By way of example, the teachings herein apply to a network based on the E-UTRA specifications, as promulgated by the 3GPP. However, that example is non-limiting, as the teachings herein apply to any network that employs in-sequence data delivery and duplicate data detection at handover. Broadly, the source base station forwards out-of-sequence SDUs and corresponding sequence number information to the target base station in support of seamless handover, and the target base station uses that information to request retransmissions as needed for packet reordering.

Claims20

Dependent claims

A method, in a wireless communication network where base stations receive protocol data units from mobile stations for ordered, sequential transfer as service data units to an associated core network, of supporting seamless handover of a mobile station from a source base station to a target base station, the method comprising:

during handover execution, the target base station receiving service data units and sequence number information forwarded from the source base station, wherein:
the forwarded service data units comprise service data units being held at the source base station for sequential transfer to the associated core network;
and
the forwarded sequence number information indicates sequence numbers corresponding to the forwarded service data units;
reordering the forwarded service data units as needed at the target base station for sequential transfer from the target base station to the associated core network.
wherein the reordering the forwarded service data units comprises the target base station:
identifying missing service data units based on the forwarded sequence number information;
and
requesting retransmission, by the mobile station, of protocol data units regenerated from the missing service data units buffered at the mobile station.

6 more elements

A target base station supporting seamless handover of a mobile station from a source base station to the target base station, in a wireless communication network where base stations receive protocol data units from mobile stations for ordered, sequential transfer as service data units to an associated core network, the target base station comprising:

an interface configured to receive service data units and sequence number information forwarded from the source base station, wherein:
the forwarded service data units comprise those service data units being held at the source base station for sequential transfer to the associated core network;
and
the forwarded sequence number information indicates sequence numbers corresponding to the forwarded service data units;
a processing circuit configured to reorder the forwarded service data units as needed at the target base station for sequential transfer from the target base station to the associated core network by:
identifying missing service data units based on the forwarded sequence number information;
requesting retransmission by the mobile station of protocol data units regenerated from the missing service data units buffered at the mobile station.

4 more elements

Dependencies are inferred from the claim text.

Method and Apparatus for Seamless Handover in a Wireless Communication Network

Life of this patent

Method and Apparatus for Seamless Handover in a Wireless Communication Network

Life of this patent

Abstract

Claims20