Multicast Service Handover Buffering for Wireless Continuity

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Solution Overview

Problem

In wireless communication networks, handovers of multicast and broadcast services from a serving base station to a target base station can result in service gaps due to differences in data packet schedules, causing users to miss content, especially when mobile stations transition between zones with different broadcast schedules.

Innovation Solution

The method involves a serving base station sending a handover request to a target base station with the last transmitted data packet and service information, allowing the target base station to buffer and send subsequent data packets, ensuring continuous service by forwarding any missed packets during the handover process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the mobile station moves from one base station coverage area to another during multicast and broadcast service reception, then the mobile station can maintain service reception, but service gaps occur due to differences in data packet schedules between base stations

Engineering Contradiction:

Improveservice continuityVSAvoidcontent reception gap

Core Design Contradiction:

ReliabilityVSLoss of information

Solution Approach 1:

The target base station receives and buffers data packets from the serving base station before the mobile station actually needs them. By preparing the data packets in advance and storing them in a buffer, the target base station ensures that no content is lost during the handover transition, even though the mobile station has not yet moved to the target base station's coverage area.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces a buffer as an intermediary component between the serving base station and the mobile station. This buffer temporarily stores data packets during the handover process, mediating the transition and ensuring continuous service delivery without gaps. The buffer acts as a temporary holding area that bridges the timing mismatch between different base stations' packet schedules.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Loss of information

If the target base station waits for the mobile station to hand over before receiving data packets, then data synchronization is maintained, but service continuity is interrupted during handover

Engineering Contradiction:

Improvedata packet synchronizationVSAvoidservice continuity

Core Design Contradiction:

Loss of informationVSReliability

Solution Approach 1:

The target base station performs preliminary actions by receiving and buffering data packets before the handover is complete. Instead of waiting passively for the mobile station to switch, the target base station proactively prepares the data packets in advance, ensuring both synchronization and continuity are maintained simultaneously.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If the mobile station receives data packets from the target base station after handover, then service continuity is maintained, but packets may be missed due to different broadcast schedules between base stations

Engineering Contradiction:

Improveservice continuityVSAvoiddata packet loss

Core Design Contradiction:

ReliabilityVSLoss of information

Solution Approach 1:

The target base station receives and buffers the complete set of data packets from the serving base station before the mobile station begins receiving packets from the target. This preliminary reception ensures that all packets, including those that would otherwise be missed due to schedule differences, are available in the buffer for subsequent delivery.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The buffer acts as a cushion that compensates for the timing mismatch between different base stations' broadcast schedules. By storing extra packets in advance, the buffer provides a safety margin that prevents packet loss during the transition, cushioning against the potential harm of schedule differences.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentUS8169972B2System and method for providing service continuity of multicast and broadcast services in a wireless communication system

Publication Date: 2012.05.01 IND TECH RES INST

AI summary

There is provided a method of handing over a provided service from a serving base station to a target base station, the service including streaming content sent to a mobile station. The method includes receiving, at the target base station, a handover request from the serving base station, the handover request identifying the streaming content being provided to the mobile station by the serving base station, and an interrupt data packet, of the streaming content, last transmitted to the mobile station. The method includes sending a handover response to the serving base station and receiving a notification from the serving base station indicating that the target base station is selected for handover. The method includes receiving, from the serving base station, subsequent data packets of the streaming content that are later in time than the interrupt data packet and sending the received subsequent data packets to the mobile station.