Q&A. Fragmentation EMAC HIMAC PHY. EMAC frames with the same HINOC destination address are combined into a HIMAC data frame

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Preston Milton Walton
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1 Q&A EMAC HIMAC1 HIMAC2 HIMAC Fragmentation FEC1 FEC2 PHY EMAC frames with the same HINOC destination address are combined into a HIMAC data frame One (or several) HIMAC data frame is carried by one FEC block of PHY The length of HIMAC Frame and FEC block are fixed Use fragmentation to improve transmission efficiency 1

2 Q&A 2+N Byte 2Byte Header Sub-frame Header (0 - N) Sub-frame (0 - N) Padding CRC Fragmentation HIMAC Frame Structure 1bit 1bit 1bit 1bit H E H E First sub-frame flag Last sub-frame flag F_FRAGMENT_H_FLAG 1bit First sub-frame Fragmentation head flag, set 1 if first sub-frame contain the first fragment of a EMAC frame. F_FRAGMENT_E_FLAG 1bit First sub-frame Fragmentation end flag, set 1 if first sub-frame contain the last fragment of a EMAC frame. L_FRAGMENT_H_FLAG 1bit Last sub-frame Fragmentation head flag, set 1 if Last sub-frame contain the first fragment of a EMAC frame. L_FRAGMENT_E_FLAG 1bit Last sub-frame Fragmentation end flag, set 1 if last sub-frame contain the last fragment of a EMAC frame. 2

3 Q&A T0 T3 TRSPONSE HB Ranging Pd Frame Pu Frame HM TDWONSTREAM TWAIT TUPSTREAM T1 Using the Pd/Pu frame of PHY to range at the beginning of the the node admission and line maintenance T2 T RTT =T DOWNSTREAM + T UPSTREAM =(T 3 -T 0 )-(T 2 -T 1 )=T RESPONSE - T WAIT T WAIT is a fixed time (interval between Pd and Pu) T RESPONSE can be measured by HB Ranging aim : 1.measure RTT. 2.HM use RTT for time delay compensation for data frame transmission. 3

4 Channel Allocation Zhang Yu, Zhang Bing, Yan Kezhou

5 Over View Channel Allocation of a MAP Cycle Report/Grant mechanism is used. Current queue information is reported to HB by each HM. According to HMs reports and local queue information, HB gives a channel plan in MAP frame which is transmitted to each HM. HB and HMs transmit data according to MAP frame. 5

6 P_IFG P_IFG P_IFG P_IFG Channel Allocation Channel Structure the entire time of channel, except for periodical slots of downlink/uplink signaling frames, is filled with non-overlapping MAP cycles. The length of Pd cycle is 65536us. The interval between Pd frame timeslot and the 5 th Pu frame timeslot is 32768us. Pd cycle Pd Pu Pd MAP cycle MAP cycle MAP cycle Pu #0 Pu #1 Pu #8 MAP cycle MAP cycle MAP cycle 6

7 Channel Allocation The 128MHz channel is divided into 8 Sub-Channel(SC) of 16MHz In 8 SCs, SC 0 is basic SC, while others are extended SC. An extended SC can be optionally configured as basic SC. Each HM uses 1 basic SC and 0-7 extended SC for data transmission In each SC, there is a MAP frame in every MAP cycle and each MAP frame indicate the next map cycle allocation of this SC. every SC s allocation is independent f SC7 MAP7 MAP7 MAP7 SC6 MAP6 MAP6 MAP6 SC5 MAP5 MAP5 MAP5 SC4 MAP4 MAP4 MAP4 SC3 SC2 SC1 SC0 MAP3 MAP2 MAP1 MAP0 MAP3 MAP2 MAP1 MAP0 MAP3 MAP2 MAP1 MAP0 (N-1)th MAP cycle Nth MAP cycle (N+1)th MAP cycle t Nth Map cycle SC0 MAP0 MAP0 MAP0 (N-1)th Map cycle Indicate 7 Indicate (N+1)th Map cycle Map cycle in channel Indicate

8 Channel Allocation MAP Cycle Structure f Downstream T_R_IFG Upstream SC7 MAP7 SC6 MAP6 SC5 MAP5 SC4 MAP SC3 MAP3 SC2 MAP2 SC1 MAP1 SC0 MAP0 3 symbols for map frame Fixed downstream Flexible down/upstream 7 symbols available for R frame Fixed upstream t 8

9 Channel Allocation An Example (If CP =1us) Fixed MAP cycle:146 OFDM symbols,140 available. HB uses 5-7th symbols to transmit MAP frame. HMs use some of the symbols between th to transmit R frame. (the number and position of the symbols used by HM is allocated by HB during node admission control and line maintenance.) 3 symbols for down/up switch,3 symbols for up/down switch. The other 130 symbols used to transmit data frame Fixed downstream: 8 symbols must be used to transmit downlink data frame. Fixed upstream: 8 symbols must be used to transmit uplink data frame. 114 symbols used flexible for downlink or uplink data frame. 9

10 HM 1 Channel allocation in TDMA and OFDMA mode Sub-carrier Sub-carrier HM 2 HM 3 OFDM symbol OFDM symbol (a) OFDMA (b) TDMA 10

11 Thank you! 11

Updates to 802.3bn EPoC Upstream Framing Proposal. Avi Kliger, Leo Montreuil Broadcom

Updates to 802.3bn EPoC Upstream Framing Proposal Avi Kliger, Leo Montreuil Broadcom Changes From Previous Version Adapt proposal to the decision to reduce RTT spread to less than a symbol size All CNUs