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【正文】 y ersSc op e ofH IPE R L A N /2stand ardsP ac ke t bas ed Comm on pa r t CLE t her SSC SI E E E 1 3 9 4 SSCSPP P/I PD ata LinkC on t rol La y erPh y si ca l La y er? Standardization scope: air interface, service interfaces of the radio access system and the convergence layer functions doc.: IEEE Submission July 2020 Jamshid KhunJush, Ericsson Slide 11 ? Segmentation and reassembly to / from 48 bytes packets ? Priority mapping from IEEE ? Address mapping from IEEE 802 ? Multicast amp。 broadcast handling ? Flexible amount of QoS classes Convergence Layer ? Multiple convergence layers ? One single convergence layer active at a time ? Mapping between higher layer connections/priorities and DLC connections/priorities Cell based ATM CP Packet based PPP Firewire Ether UMTS Common Part (CP) Service Specific Part DL C:PH Y:DLC SDU, 3 9 6 b it s C R CHead erHig h er la y er p ac k et ( e. g . Et h er n et p ac k et)Flag s , 1 2 b its P ay lo ad , 3 8 4 b it sDLC SDU C R CHead erFlag s , 1 2 b its P ay lo ad , 3 8 4 b it sP r ea m b l e SC H SC H L C H L C HDLC L C H P DU, 4 3 2 b it sCL :P HY b u r s tSC H SC H L C H L C HL C HMapping higher layer packets onto layers of HiperLAN/2 doc.: IEEE Submission July 2020 Jamshid KhunJush, Ericsson Slide 12 DLC: Medium Access Control 1 ? TDMA/TDD with a fixed frame duration of 2 ms ? 3 transmission possibilities: AP to MT (Downlink), MT to AP (Uplink) and MT to MT (Direct Link) ? Centralized scheduling (not specified) – Air interface frame creation in the AP – Resource allocation by the AP – Resource requests from MTs – Dynamic assignment of capacity in uplink and downlink no fixed slot structure is mandatory, but possible for CBR type services – Could consider QoS and link adaptation modes – Transmission of Data PDU and ARQ PDU without collisions ? Peertopeer and multicast support doc.: IEEE Submission July 2020 Jamshid KhunJush, Ericsson Slide 13 DLC: Medium Access Control 2 ? Random access scheme – Association and resource request transmissions from MTs – Random access in mobile stations: slotted ALOHA with exponential increase of contention window – Processing random access in the AP: acknowledgements of random access in the next frame ? Sector antenna support doc.: IEEE Submission July 2020 Jamshid KhunJush, Ericsson Slide 14 MAC Frame Channels: Logical Channel 1 Logical and Transport channels are used to construct MAC frame ? Logical Channel: – A generic term for any distinct data path which describes a specific data transfer service offered by the MAC entity – Defined by the type of information it carries and the interpretation of the value in the corresponding messages ? Some important Logical Channels – BCCH (Broadcast Control CHannel): used in downlink conveying the necessary broadcast information concerning the whole radio cell . scrambler seed, access point ID, work ID, etc. – FCCH (Frame Control CHannel): used in downlink conveying information describing the structure of the MAC frame visible at the air interface (resource grant announcement) – RACH (Random Access CHannel): used by MTs in uplink to send signalling data (resource request, association request) for DLC or RLC. doc.: IEEE Submission July 2020 Jamshid KhunJush, Ericsson Slide 15 MAC Frame Channels: Logical Channel 2 ? Some important Logical Channesl: Contd – RFCH (Random access Feedback CHannel): used in downlink to inform the MTs that have used the RACH in the previous MAC frame about the result of their access attempts. – RBCH (RLC Broadcast CHannel): used in downlink (when necessary) conveying broadca
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