Prioritized MAC Access Mechanism of Routing-related Frame for ESS Mesh

1. Prioritized MAC Access Mechanism of Routing-related Frame for ESS Mesh SK Sung, Samsung Electronics s.sung@samsung.com

2. Introduction Requirement and recommendation for Mesh NW An open problem on QoS Mesh QoS Example: A prioritized MAC access mechanism of routing-related frames for mobile ad hoc network Independent BSS case ESS Mesh case Conclusion Overview

3. Samsung is basically supportive for the ESS mesh network standardization efforts. We recommend an enhanced quality of service in mesh networking by adopting efficient channel access scheme, which considers specific features of protocol frame. Motivation

4. ESS Mesh, a broad chance of mobile application Interactive ad hoc gaming, chatting,…. Instant messaging (ex. PoW) Car-oriented application (emergency propagation) QoS Requirements of mobile ad hoc Mesh NW Throughput Latency Security Reliability Introduction

5. Factors affecting on the latency in ESS Mesh network Routing algorithm Channel access mechanism Location of routing protocol and more… Workscope of ESS mesh PAR covers MAC amendment/extension, which can render efficient channel access possible Introduction

6. Prioritized channel access for routing-related frame Configure fast and efficient ad hoc routing path Potentially reduce packet loss via fast link setup Application Application IP IP MARP Core MARP Core C MAC MAC B PHY PHY MARP: Mobile Ad hoc Routing Protocol Advantage of prioritized routing access

7. 802.11 MAC access mechanism Contention-based and contention free strategy For infrastructure BSS, AP, as PC, is generally vested with the control of coordination functions Discriminatory IFS according to PCF/DCF Prioritized access to medium through PCF For independent BSS case, all the STAs will basically have equal chance of channel access using DIFS, though have random backoff procedure. 802.11 MAC

8. To obtain fast channel access for automatic topology learning and dynamic path configuration, whether SG MES will take complete adoption of QoS-enhanced features from 11e, or simply make minor amendment reflecting ESS mesh-specific requirement from the current MAC Features of 11e draft, Enhanced channel access using EDCA/HCCA HCF reflecting UP Hybrid and complicated entity/function for QoS Open Issues?

9. We suggest QoS based MAC Access Scheme for ESS mesh Prioritized medium access mechanism for routing-related frame The MAC amendment be independent on the information that in which layer the ad hoc routing protocol exists, but recommended to be placed at lower layers(L3 or L2.5) considering latency Conclusion

10. Back UpExamples of Prioritized Access for routing related frame IBSS Ad hoc WDS

11. Independent BSS(IBSS) Prioritized medium access using shorter IFS SIFS< MCIFS (MARP control IFS) < DIFS Guaranteed access priority than ‘Random Backoff Time’ Contention Window DIFS (data frame) Slot time MCIFS (control frame) DIFS Busy Medium SIFS Backoff Window Next Frame Select slot and decrement backoff as long as medium is idle Defer Access Prioritized IFS scheme for MANET- IBSS Network Access Method for IBSS

12. Access and backoff procedure Prioritized IFS scheme for MANET- IBSS Data Frame Station A DIFS Defer Defer MANET data frame Station B MCIFS Defer Station C MANET control frame DIFS DIFS Defer Defer Station D MANET data frame Backoff procedure for IBSS

13. Example of introducing MCIFS flag in existing 802.11 MAC format Frame Control Duration ID Addr 1 Addr 2 Addr 3 Sequence control Addr 4 Frame body FCS More Frag Retry PWR Mgt More data WEP Order Protocol Ver. To DS From DS Type Subtype Prioritized IFS scheme for MANET- IBSS b2 b3 b4 b7 The reserved bits in this field can be used whether the incoming frame is MANET control frame or MANET data frame e.g) 000110~001110,001011~001111,101000~101111

14. Valid Type and Subtype field

15. Hosting AP functions in ad hoc WDS Inherit general AP functions Constructs/Reconfigure ad hoc DS Construction of wireless backbone network Recommended to provide prioritized access to DCF/PCF at BSS Ad hoc WDS AP#n Internet AP#2 Router AP#4 802.3D LAN AP#1 Bridge AP#3

16. Ad hoc DS formation scheme prior to normal access mechanism Prioritized medium access using shorter IFS Ex.1) SIFS< MCIFS = PIFS < DIFS Ex.2) SIFS< MCIFS < PIFS < DIFS Guaranteed access priority than ‘Random Backoff Time’ Prioritized IFS scheme for MANET- ad hoc WDS

17. Example 2 SIFS< MCIFS < PIFS Prioritized IFS scheme for MANET- ad hoc WDS DIFS (data frame) Contention Window PIFS (data frame) Slot time MCIFS (control frame) DIFS Busy Medium Backoff Window Next Frame SIFS Select slot and decrement backoff as long as medium is idle Defer Access Network Access Method for adhoc WDS

18. Pros MANET route can be constructed relatively fast due to less contention when accessing medium Mitigates data loss due to delayed MANET routing construction Possibly, allows faster node mobility Cons Required is algorithm/equipment to decide whether incoming frame is MANET control or data frame Pros and cons

19. Mobile Ad hoc Network (MANET) MANET examples with regard to WLAN Independent BSS, ad hoc WDS MANET routing algorithm generally discovers dynamic topologies and configures path using link metric information Each node has a self-configuring and healing functionality When initiating MANET routing algorithm, the exchange of routing-related frame is recommended to have priority to other data traffic frame. Introduction

20. MANET frame and stack MANET control frame Information for routing algorithm PHY aware metric Routing path MANET data frame Lower layer data unit MARP Core Adhoc Routing Protocol Application IP MAC PHY