Directional RTS Reception During Beam Sweep in 802.11ad Networks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication systems, especially those compliant with the IEEE 802.11ad standard, network congestion arises due to interference from multiple devices transmitting Request to Send (RTS) messages simultaneously, leading to increased overhead in RTS/CTS signaling and overall network congestion, as intended recipients may not respond to RTS messages due to overestimated interference.
Innovation Solution
The receiving device performs a beam sweep in determined spatial directions to detect RTS messages, allowing multiple transmissions of RTS messages or longer duration RTS messages, enabling detection during the beam sweep interval, thereby reducing network congestion and improving medium reuse.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If receiving devices remain in omni-directional mode to receive RTS messages, then all RTS messages can be received, but network congestion increases and medium reuse decreases due to interference from multiple simultaneous transmissions
Solution Approach 1:
The receiving device segments the reception process by performing beam sweeps in multiple spatial directions during beamforming training phases. This allows the receiver to directionally detect RTS messages from different transmitters sequentially, reducing interference effects and enabling more efficient medium access control in dense wireless networks
Solution Approach 2:
The receiving device performs preliminary beamforming training to determine spatial directions of potential transmitters before the actual data transmission phase. This preliminary action enables the receiver to configure its beam sweep pattern in advance, ensuring it can detect RTS messages from multiple directions during the CBAP while reducing interference from simultaneous transmissions
2Productivity
If multiple devices transmit RTS messages simultaneously, then channel access efficiency improves, but interference increases causing intended recipients to fail to transmit CTS messages
Solution Approach 1:
The receiving device applies local quality by configuring beam sweeps in specific spatial directions based on determined transmitter locations. Instead of uniform omnidirectional reception, the receiver focuses its detection capability in directions where transmitters are located, allowing simultaneous RTS messages from multiple devices to be detected with reduced interference effects
Solution Approach 2:
The receiving device converts the harmful effect of simultaneous RTS transmissions into a benefit by using beam sweeps to directionally detect each RTS message. The interference that would normally cause detection failures is transformed into an opportunity to identify multiple active transmitters through spatial filtering, improving overall channel access efficiency
Data Source
Figure 1
Figure 2A~2D
Figure 3
AI summary
Methods and apparatus that support controlled transmission and directional reception of RTS and/or CTS messages, are described. Controlled transmission may include transmitting a same RTS message multiple times in the same direction and/or transmitting an RTS message with a length that is multiple times longer than a standard RTS message. In an aspect, a receiver may determine spatial directions of a plurality of transmitters including a first transmitter and at least one other transmitter, and may perform a beam sweep in the determined spatial directions for receiving one or more RTS messages. A transmitter may determine that a receiver is to perform a beam sweep in K different spatial directions, and may transmit a same RTS message for a data transmission K times in the same direction or an RTS message with a length approximately K times longer than a standard RTS message, during a duration of the beam sweep.