Method and apparatus for base-initiated, CDMA-dispatch soft handoff
First Claim
1. A method for a base site to initiate a CDMA-dispatch soft handoff comprising the steps of:
- establishing a first outbound link for a dispatch call;
transmitting the dispatch call via the first outbound link;
establishing an inbound link with a mobile station (MS) for the dispatch call;
determining based on a signal quality of the in-bound link that the MS should begin a soft handoff;
determining at least one base site of a plurality of adjacent base sites for the MS to begin a soft handoff with; and
indicating to the MS an identity of the at least one base site and an identity of an outbound link for the dispatch call at the at least one base site, wherein the step of indicating the identity of the at least one base site and the identity of an outbound link comprises signaling in one of the manners of signaling that are included in the group consisting of signaling in-band on the first outbound link and signaling via a paging channel.
4 Assignments
0 Petitions
Accused Products
Abstract
To address the need for an apparatus and method for CDMA-dispatch soft handoff, the present invention enables base-initiated soft handoff for dispatch calls. A mobile station (120) in a dispatch call establishes an individual inbound link (137) with the serving base site (111). The serving base site and one or more adjacent base sites (e.g., 110 and 112) determine the signal quality of the inbound link transmissions of the mobile station. The adjacent base site with the highest received inbound link signal quality is selected as the target soft handoff site. The serving base site then transmits the handoff information to enable the mobile station to begin a soft handoff with the target site.
56 Citations
18 Claims
-
1. A method for a base site to initiate a CDMA-dispatch soft handoff comprising the steps of:
-
establishing a first outbound link for a dispatch call; transmitting the dispatch call via the first outbound link; establishing an inbound link with a mobile station (MS) for the dispatch call; determining based on a signal quality of the in-bound link that the MS should begin a soft handoff; determining at least one base site of a plurality of adjacent base sites for the MS to begin a soft handoff with; and indicating to the MS an identity of the at least one base site and an identity of an outbound link for the dispatch call at the at least one base site, wherein the step of indicating the identity of the at least one base site and the identity of an outbound link comprises signaling in one of the manners of signaling that are included in the group consisting of signaling in-band on the first outbound link and signaling via a paging channel. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A base site comprising:
-
a receiver; a transmitter; and a controller, coupled to the receiver and the transmitter, adapted to establish a first outbound link for a dispatch call, adapted to instruct the transmitter to transmit the dispatch call via the first outbound link, adapted to establish an inbound link with a mobile station (MS) for the dispatch call using the receiver, adapted to determine based on a signal quality of the inbound link that the MS should begin a soft handoff, adapted to determine at least one base site of a plurality of adjacent base sites for the MS to begin a soft handoff with, and adapted to indicate to the MS using the transmitter an identity of the at least one base site and an identity of an outbound link for the dispatch call at the at least one base site, wherein the controller instructs the transmitter to transmit signaling to indicate the identity of the at least one base site and the identity of an outbound link in one of the manners of signaling that are included in the group consisting of signaling in-band on the first outbound link and signaling via a paging channel. - View Dependent Claims (13, 14, 15, 16, 17, 18)
-
Specification