Wireless Mesh Border Router Time Division Multiplexing

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Border routers in wireless mesh networks face challenges in seamlessly transitioning between IEEE 802.15.4 and IEEE 802.11 protocols while maintaining efficient packet forwarding and signaling availability to devices within the network, especially when operating with a single RF chain and using time division multiplexing.

Innovation Solution

The border router employs time division multiplexing to operate as both an IEEE 802.15.4 coordinator and an IEEE 802.11 wireless station, using beacons in beacon-enabled modes to signal availability and transitions, and layer-4 UDP packets in beaconless modes to manage operations, ensuring non-overlapping durations for each protocol and maintaining network connectivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If time division multiplexing is used to operate with a single RF chain for both IEEE 802.15.4 and IEEE 802.11 protocols, then device complexity and cost are reduced, but seamless transition between protocols and efficient packet forwarding become challenging

Engineering Contradiction:

ImproveRF chain configurationVSAvoidprotocol transition reliability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The border router implements periodic switching between IEEE 802.15.4 coordinator mode and IEEE 802.11 station mode using time division multiplexing. The router alternates between protocols in defined time intervals, allowing a single RF chain to serve both protocols reliably without requiring simultaneous operation, thus reducing complexity while maintaining transition reliability

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The system dynamically transitions the RF chain between different operational modes (802.15.4 coordinator and 802.11 station) based on time-scheduled events. This dynamic switching enables the single RF chain to adapt its behavior to match protocol requirements at different times, resolving the contradiction between simplicity and reliable protocol operation

Inventive Principle:

Principle #15Dynamics

2Device complexity

If a border router uses time division multiplexing to switch between IEEE 802.15.4 and IEEE 802.11 protocols, then hardware requirements are reduced, but packet forwarding efficiency and signaling availability may deteriorate

Engineering Contradiction:

Improvehardware requirementsVSAvoidpacket forwarding efficiency

Core Design Contradiction:

Device complexityVSProductivity

Solution Approach 1:

The border router performs preliminary actions by scheduling and buffering packets before protocol transition periods. packets destined for external networks are queued during 802.15.4 operation and transmitted during 802.11 operation, and vice versa. This preliminary buffering ensures that packet forwarding efficiency is maintained despite the sequential nature of time division multiplexing

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system maintains continuous useful action by ensuring that packet forwarding operations continue uninterrupted across protocol boundaries. The time division multiplexing schedule is designed to minimize idle periods, and packet buffering mechanisms ensure that forwarding operations resume immediately after each protocol switch, maintaining overall productivity despite the alternating protocol operation

Inventive Principle:

Principle #20Continuity of useful action

3Loss of information

If the border router operates in beacon-enabled mode with IEEE 802.15.4, then availability signaling to devices is improved, but power consumption and operational complexity increase

Engineering Contradiction:

Improveavailability signalingVSAvoidpower consumption

Core Design Contradiction:

Loss of informationVSUse of energy by moving object

Solution Approach 1:

The border router uses IEEE 802.11 beacon frames to serve multiple functions: they provide availability signaling to 802.15.4 child devices during 802.11 operation periods, replacing the need for separate 802.15.4 beacons during those intervals. This multi-functional approach maintains information signaling while reducing overall power consumption by leveraging the already-active 802.11 RF chain

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS10104596B2Border router of a wireless mesh network extending connectivity of wireless stations to external networks

Publication Date: 2018.10.16 GAINSPAN CORP

AI summary

A wireless device receives a sequence of packets in a first set of durations on a first wireless network according to a first wireless protocol. The border router forwards the received sequence of packets in a second set of durations on a second wireless network according to a second wireless protocol. None of the first set of durations overlaps with any of the second set of durations. The first set of durations and the second set of durations are realized according to time division multiplexing. The sequence of packets are received and forwarded by the wireless device using a shared transceiver. In an embodiment, the wireless device is a border router of a wireless mesh network, and the first wireless protocol and the second wireless protocol are respectively according IEEE 802.15.4 and IEEE 802.11.