Transcript tictoc-4
Synchronization Requirements for RAN & Backhaul Update draft-zhou-tictoc-ran-sync-req-01.txt Xiaodong Duan, Lan Wang China Mobile Version Update • New version submits – draft-zhou-tictoc-ran-sync-req-01.txt • Update – Phase sync accuracy of RAN system in TD-SCDMA reaches agreement • Accuracy among NodeBs: 3us • Accuracy between NodeB and reference clock: 1.5us – Phase sync accuracy of RAN system in TD-LTE is under discussion • Accuracy among NodeBs: 1~3us – Requirements for 1588v2 backhaul Requirements Update Base station UE Base station controller UE Radio Interface SYNC Node SYNC Ref. Clock Network SYNC Base station Layer Sub Items Frequency Accuracy Phase Accuracy Network Sync E1 50ppm - STM-N 4.6ppm - PTN Not so strict - Controller-Base station If provide location service, TBD If provide location service, TBD 50ppb(Time alignment over Iu) 1.5us(Time alignment over Iu) Inter-Base station 50ppb 3us(TD-SCDMA&TDD LTE) BS-Reference clock 50ppb 1.5us(TD-SCDMA&TDD LTE) GSM 50ppb - TD-SCDMA 50ppb 3us TDD LTE 50ppb 1-3us Node Sync Radio interface Urgent requirements for RAN Sync • Most operators have choice LTE as their evolution of 2/3G network – TDD based LTE has just been introduced – TDD LTE has higher sync requirement than FDD • The requirements for RAN is clear and urgent – Radio Access Network is on the early stage of moving to IP transport – GPS is the only solution so far • The total technologies/solutions should be deployed within one year----Urgent!! – TICTOC should accelerate its work Example: Current 3G/TD-SCDMA Networks ATM NodeB SDH RNC ATM NodeB • Currently, each nodeB has a GPS antenna--Not so good! – COST: you can imagine 10000 BSs in one city – Uneasy deployment: affect the flexible deployment of BS – Other • Security/Reliability Mobile backhaul 802.1ad/ PON / MPLS PBT/ TMPLS/ MPLS/ Access VPLS/ IP IP/MPLS Core Aggr RNC Core RNC NodeB 802.1ad IP/MPLS core PBT PON NodeB DLS NodeB RNC NodeB RNC TMPLS IP/MPLS core TMPLS TMPLS NodeB RNC NodeB MPLS AGG VLL/VPLS 802.1ad NodeB RNC MPLS Access IP/MPLS core Backhual sync transmission • Two sync transmission mode should be considered – Core network sync distribute—sync are distributed to local clock • 1588v2 over IP/MPLS core – Core to edge- local clock are distributed to Edge Node (such as BS) • IEEE1588 or other must be extend to used within different backhaul technology, such as – – – – – • The protocols designed by TICTOC should considered – – – – • MPLS/IP PON 802.1 PBT TMPLS Reliable transmission Security Retransmission/Verification Suit for different kinds of backhaul How to Work with Multicast Technologies to reduce overhead Summary • RAN requirements for sync are more clearly now and TD based LTE has high sync requirements • It better for us to provide solutions with 1years, so that the industry can used it ASAP • Most operators are replanning their Mobile Backhaul to meet the high bandwidth, the sync protocol should be considered • Telecom profiles of sync protocol – network scale/ network load/ local clock accuracy – Reliable transport/ security/ efficiency/ Retransmission/Verification – Multicast Thank you& Any questions?