IEEE 802.11 NAV Mechanism for Bluetooth Coexistence
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Solution Overview
Problem
Collocated IEEE 802.11 and Bluetooth transceivers often interfere with each other's operation, especially when one is operating as an access point, leading to high packet error rates and unacceptably low throughput due to insufficient coexistence techniques.
Innovation Solution
The use of the Network Allocation Vector (NAV) mechanism in IEEE 802.11 transceivers to prevent simultaneous transmission with Bluetooth transceivers, by setting the NAV of associated devices to inhibit transmission during critical Bluetooth activity periods, allowing Bluetooth to operate without interference from IEEE 802.11 transceivers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If IEEE 802.11 and Bluetooth transceivers operate simultaneously in close vicinity, then both transceivers can provide wireless communication functionality, but transmission collisions and mutual interference occur leading to high packet error rates and low throughput
Solution Approach 1:
The patent applies preliminary action by setting the Network Allocation Vector (NAV) in advance before Bluetooth transmissions occur. The IEEE 802.11 access point sends a frame with a duration field that specifies the time period during which Bluetooth will be active, causing receiving IEEE 802.11 transceivers to update their NAV and defer transmissions until the NAV timer expires. This preemptive timing mechanism prevents collisions before they can occur.
Solution Approach 2:
The patent uses the NAV mechanism as an intermediary to mediate between IEEE 802.11 and Bluetooth transmissions. The duration field in the IEEE 802.11 frame acts as a signaling intermediary that communicates the intended Bluetooth transmission period to other IEEE 802.11 devices, enabling them to automatically adjust their transmission behavior without direct interference management.
2Reliability
If IEEE 802.11 transceivers use NAV mechanism to avoid simultaneous transmission with Bluetooth, then packet errors are reduced, but transmission delays may increase due to deferred transmissions
Solution Approach 1:
The patent employs periodic action by organizing IEEE 802.11 transmissions into periodic time periods that alternate with Bluetooth transmission periods. The NAV mechanism creates structured time slots where IEEE 802.11 transmissions are deferred during Bluetooth activity but resume afterward, establishing a rhythmic transmission pattern that balances both protocols' needs.
Solution Approach 2:
The patent applies dynamics by making the IEEE 802.11 transmission behavior adaptive rather than static. The NAV timer value dynamically adjusts based on the duration field received in frames, allowing the deferral period to change according to actual Bluetooth transmission requirements. This dynamic adjustment optimizes the balance between avoiding interference and minimizing transmission delays.
Data Source
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AI summary
The present invention comprises a communication device configured to communicate using several wireless networking protocols. The communication device is configured to transmit a signal according to a first protocol so as to indicate to devices on the wireless network that they should not transmit during a first period of time, and subsequently, transmit or receive signals by means of the second protocol during the first period of time.