Method and system for management of inter-frequency handoff

A method comprising:

• a radio access network (RAN) serving one or more mobile stations through air interface communication on a first frequency channel;
• while serving the one or more mobile stations through air interface communication on the first frequency channel, the RAN applying a pre-selection process to dynamically pre-select a preferred second frequency channel to be used as a handoff target, wherein the pre-selection process comprises (i) receiving from the one or more mobile stations reports of air interface quality measured by the one or more mobile stations on second frequency channels and (ii) using the received reports as a basis to select one of the second carrier frequency channels as the preferred second frequency channel;
• and
• subsequent to applying the pre-selection process, the RAN detecting that a particular one of the one or more mobile stations is fading from coverage on the first frequency channel, and in response to the detecting, (a) the RAN requesting the particular mobile station to determine and report to the RAN measurements of sector quality on the dynamically pre-selected second frequency channel, (b) the RAN receiving in response from the particular mobile station the requested measurements of sector quality on the dynamically pre-selected second frequency channel, (c) based on the received measurements of sector quality on the dynamically pre-selected second frequency channel, the RAN selecting a target sector on the dynamically pre-selected second frequency channel, and (d) the RAN directing the particular mobile station to hand off to the selected target sector on the dynamically pre-selected second frequency channel.

A radio access network (RAN) comprising:

• base stations radiating to provide coverage for served mobile stations on a plurality of frequency channels, wherein a given base station serves one or more mobile stations on at least a first frequency channel;
• pre-selection logic executable by the RAN, while the given base station is serving the one or more mobile stations on the first frequency channel, to dynamically pre-select a preferred second frequency channel to be used as a handoff target, by (i) receiving via the given base station, from the one or more mobile stations, reports of air interface quality measured by the one or more mobile stations on second frequency channels and (ii) using the received reports as a basis to select one of the second carrier frequency channels as the preferred second frequency channel;
• and
• handoff logic executable by the RAN to detect that a particular one of the one or more mobile stations is fading from coverage on the first frequency channel, and in response to the detecting, (a) to request the particular mobile station to determine and report to the RAN measurements of sector quality on the dynamically pre-selected second frequency channel, (b) to receive in response from the particular mobile station the requested measurements of sector quality on the dynamically pre-selected second frequency channel, (c) based on the received measurements of sector quality on the dynamically pre-selected second frequency channel, to select a target sector on the dynamically pre-selected second frequency channel, and (d) to direct the particular mobile station to hand off to the selected target sector on the dynamically pre-selected second frequency channel.

A method comprising:

• while a cellular radio access network (RAN) is serving one or more mobile stations in a first sector defined by the RAN, the RAN collecting from the one or more mobile stations measurements of air interface quality of a plurality of frequency channels of surrounding sectors;
• the RAN using the collected measurements as a basis to select a preferred frequency channel to use as a handoff target;
• the RAN detecting that a particular mobile station is fading from coverage of the first sector;
• and
• responsive to the detecting, (i) the RAN requesting the particular mobile station to determine and report to the RAN measurements of sector quality on the selected frequency channel, (ii) the RAN receiving in response from the particular mobile station the requested measurements of sector quality on the selected frequency channel, (iv) the RAN selecting a target sector based on the received measurements of sector quality, and (v) the RAN directing the particular mobile station to hand off from the first sector to the selected target sector on the selected frequency channel.