Relay Entity Multicast Delivery in Wireless LAN
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Solution Overview
Problem
The existing WLAN systems lack a specific protocol for supporting relays, particularly in multicast/broadcast operations, which is crucial for efficient M2M communication and network coverage extension, especially with low-cost, low-complexity, and low-power devices.
Innovation Solution
A method and apparatus for delivering multicast/broadcast frames in a WLAN system using a relay entity, where the frames are received from a station, processed, and transmitted to a root access point within a basic service set, with specific address fields configurations to ensure correct routing and efficient delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a relay is introduced to extend wireless coverage in WLAN system, then network coverage is extended, but protocol complexity increases due to lack of specific relay support protocol
Solution Approach 1:
The relay station is designed to operate with universal functionality, acting as both a non-AP STA with respect to an AP and as an AP with respect to other non-AP STAs. This multi-role capability allows the relay to extend network coverage while using existing WLAN protocols without requiring separate dedicated protocols, thereby reducing overall protocol complexity.
Solution Approach 2:
The relay station serves as an intermediary entity that bridges between the AP and remote STAs. It receives frames from non-AP STAs and forwards them to the AP, and vice versa, enabling coverage extension through a mediating node that uses standard WLAN protocols for both uplink and downlink communications.
2Device complexity
If relay protocol is simplified for low-cost devices, then device complexity is reduced, but multicast/broadcast functionality may be compromised
Solution Approach 1:
The relay station performs self-service by autonomously handling multicast/broadcast frame delivery without requiring complex external coordination. It receives multicast/broadcast frames from the AP and independently delivers them to associated non-AP STAs using simplified protocols, maintaining functionality while reducing device complexity.
Solution Approach 2:
The relay protocol is segmented into distinct operational modes: unicast frame handling, multicast/broadcast frame delivery, and acknowledgment mechanisms. This segmentation allows low-cost devices to implement only the essential simplified protocols needed for their specific function while maintaining support for multicast/broadcast through dedicated simplified procedures.
3Adaptability or versatility
If relay station acts as AP for non-AP STAs, then network flexibility is improved, but address management complexity increases
Solution Approach 1:
The relay station dynamically adapts its role and address usage based on the communication direction. When communicating with non-AP STAs, it acts as an AP using its own MAC address as BSSID. When communicating with the AP, it acts as a non-AP STA. This dynamic role switching simplifies address management by using context-dependent address assignment rather than requiring complex static configurations.
Solution Approach 2:
The relay station changes its operational parameters including MAC address usage and BSSID assignment based on the communication context. It uses different MAC addresses for different interfaces and roles, allowing flexible network operation while maintaining simple address management through parameter adaptation rather than complex permanent configurations.
Data Source
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AI summary
The present disclosure relates to a wireless communication system and, more particularly, to a method and apparatus for multicasting/broadcasting in a relay network of a wireless LAN system. A method by which a relay entity delivers a multicast/broadcast frame in a wireless LAN system, according to one embodiment of the present disclosure, includes the steps of: receiving a multicast/broadcast frame from an STA; and delivering the multicast/broadcast frame to a root access point (AP). The multicast/broadcast frame may be transmitted by the root AP in a broadcast scheme within a basic service set (BSS). In the multicast/broadcast frame transmitted in the broadcast scheme by the root AP, an address 1 (A1) field may be set to a multicast/broadcast address, an address 2 (A2) field may be set to a medium access control (MAC) address of the root AP, and an address 3 (A3) field may be set as a MAC address of the STA, which is a source address of the multicast/broadcast frame.