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 Base station controller Base station UE Radio Interface SYNC Ref. Clock Network SYNCNode SYNC LayerSub ItemsFrequency AccuracyPhase Accuracy Network SyncE150ppm- STM-N4.6ppm- PTNNot so strict- Node SyncController-Base station If provide location service, TBD 50ppb(Time alignment over Iu)1.5us(Time alignment over Iu) Inter-Base station50ppb3us(TD-SCDMA&TDD LTE) BS-Reference clock50ppb1.5us(TD-SCDMA&TDD LTE) Radio interfaceGSM50ppb- TD-SCDMA50ppb3us TDD LTE50ppb1-3us

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 RNC NodeB SDH ATM Currently, each nodeB has a GPS antenna--Not so good! –COST: you can imagine BSs in one city –Uneasy deployment: affect the flexible deployment of BS –Other Security/Reliability

Mobile backhaul IP/MPLS core RNC PBT 802.1ad DLS PON RNC IP/MPLS core RNC TMPLS RNC TMPLS RNC IP/MPLS core RNC MPLS AGG VLL/VPLS MPLS Access 802.1ad CoreAggrAccess NodeB 802.1ad/ PON / MPLS PBT/ TMPLS/ MPLS/ VPLS/ IP 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 –MPLS/IP –PON –802.1 –PBT –TMPLS The protocols designed by TICTOC should considered –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?