1588 v 2 modules of time synchronization with

1588 v 2 modules of time synchronization with frequency layer support draft-su-tictoc-1588 v 2 -time-sync-modules-00 IETF 75 th, Stockholm TICTOC WG su. fei@zte. com. cn 1

Motivation p 1588 v 2 has being deployed in TD-SCDMA backhaul network for decreasing the use of GPS p Profiles of 1588 v 2 system in this application should be outlined in appropriate document p ITU-T Q 13/15 also has intension to specify the 1588 v 2 telecom profiles for time/phase sync with frequency sync support (architecture preliminarily ) 2

Structure of document p Introduction p Scenario of 1588 v 2 time/phase sync for TD-SCDMA backhaul p Time/phase server p PTP client p Timestamping process 3

Introduction p Time/phase requirement of TD-SCDMA has been recognized both in IETF TICTOC (draft-ietf-tictoc-requirements-00. txt) and ITU-T Q 13/15 (G. 8266) p To endure stringent time/phase alignment between Node. B and RNC (+/-1. 5 us) over a long span metro network (e. g. 30+ nodes maximum between some Node. Bs and RNC), the time/phase sync is primarily considered to be coupled with frequency sync by operators 4

Scenario of 1588 v 2 time/phase sync for TDSCDMA backhaul p The time/phase server synchronized by GPS and/or Compass is placed near RNC p PTP client is implemented in Node. B or NEs connected to Node. B p PTP client and all NEs on the time/phase distribution path has the same frequency traceability to PTP server or higher frequency reference through Sync. E links 5

Time/phase server p Synchronized by other external time/phase source using varied time/phase interface (e. g. 1 PPS+To. D, PTP, DCLS, IRIG). Support input antenna/cable delay compensation p Provide multiple time/phase output interfaces (inter/intra office) and capacity of dealing with certain amount of PTP clients p Frequency input for time/phase holdover and frequency output interfaces (e. g. 2 Mbits and/or Sync. E) p Sync performance monitoring and management 6

PTP Client p Frequency reference selection and locking for measurement of local time/phase p Time/phase calibration based on offset calculation carried out by PTP protocol 7

Timestamping process p Distributed timestamping scheme can be used to minimize the system delay of PTP event messages p PTP event message is timestamped by edge timestamping unit close to physical interface p The transient delay of PTP message directly forwarded (without being processed by PTP protocol unit) can be accurately measured and compensated 8

Timestamping process p Example of timestamping operations using delay request-response mode • Ingress PHY interface 9

Timestamping process • Egress PHY interface 10

What’s next p Improve contents of the document based on discussions or comments from those who have interests p Consider other aspects of the application e. g. sync protection, management, security etc. p Merged with existing I-D “draft-su-tictoc-time-sync-mode-01” which has the consistency with this one 11