CPRI-T (Fronthaul through transport of CPRI signal from RRH to the C-RAN baseband.) 23-07-2015 Jishnu Aravindakshan

©Tejas Networks Proprietary & Confidential What is Fronthaul (FH)? Cellsite Cellsite Antenna Centralized CoMP (C-RAN) Architecture Antenna RRH Fronthaul RRH Cellsite BBU Antenna BBU To backhaul To backhaul Hubsite Existing distributed Architecture RRH < 20 Km ©Tejas Networks Proprietary & Confidential

Ref Note: Extracted from CPRI v6.1 requirements CPRI (Common public Radio Interface) is a standard interface used to connect Radio Equipment Controller/REC (BBU) with one or more of Radio Equipment/RE through single or multiple hop technologies The current standard is CPRIv6.1 published on 01/07/2014 The physical layer can support both electrical and optical interface. For fronthaul we will be concerned with only optical interface This specification defines the Layer 1 (optical characteristics, flow multiplexing, low level signaling) and Layer 2 (MAC, Flow control, data protection of control and management flow) CPRI operates at a basic frame rate of 3.84MHz or UMTS chip rate of 3.84 Mbps http://www.cpri.info/downloads/CPRI_v_6_1_2014-07-01.pdf Ref Note: Extracted from CPRI v6.1 requirements

CPRI REC and RE for E-UTRA http://www.cpri.info/downloads/CPRI_v_6_1_2014-07-01.pdf Ref Note: Extracted from CPRI v6.1 requirements

Ref Note: Extracted from CPRI v6.1 requirements CPRI Frame Basics CPRI Option Data Rate 1 614 Mbps 2 1.28 Gbps 3 2.45 Gbps 4 3.07 Gbps 5 4.92 Gbps 6 6.14 Gbps 7 9.83 Gbps 7A 8.11 Gbit/s (64B/66B) 8 10.13 Gbps (64B/66B) 9 12.16 Gbps (64B/66B) Basic frame duration = 1/3.84 ~ 260.41 ns Basic word consist of 16 words; W = 0 to 15 Length of the word (T) is based on the CPRI line rate. It varies from 8 bit (CPRI1) to 192 bit (CPRI9) W=0 is used for control word (CW), W=1to 15 is used for IQ sample transmission CW is equal to T for CPRI 1-7,7A but is equal to 128 for CPRI 8,9 http://www.cpri.info/downloads/CPRI_v_6_1_2014-07-01.pdf Ref Note: Extracted from CPRI v6.1 requirements

©Tejas Networks Proprietary & Confidential CPRI-T For CPRI transport the following consideration will be important Topology and resiliency CPRI supports point-to-point, chain, tree and ring topology In case of CPRI-T, Ring topology will the most appropriate to handle the link failure in case of optical fiber In case of MW backhaul point-to-point link may be a viable option due to the distance and capacity constraints of radio link Capacity and Range MW : 18-42 GHz or E-band (70-80 GHz ) : Range (100m to max of 7 km) and Capacity (CPRI 1-3). Optical : Range (Can support 20 Km and even more), Capacity (CPRI 1-9) Latency requirement One way delay of 250us for new BS (and 100us for existing equipment) CPRI-T BER < 10-12 https://www.ngmn.org/uploads/media/NGMN_RANEV_D4_BH_FH_Evolution_V1.01.pdf ©Tejas Networks Proprietary & Confidential

CPRI-T Technology Option Dark fiber (Not viable from an opportunity cost perspective) Passive WDM xPON (Asymmetric make it unsuitable for fronthaul) WDM PON or Injection locked SFP (Not manageable) Active WDM : 20 Km distance does not need this option Microwave (Short distance) Circuit emulation over Ethernet OTN ©Tejas Networks Proprietary & Confidential

CPRI-T FaaS (Fronthaul as a service) Native transport of CPRI Ability to multiplex WiFi Backhaul (BH) with CPRI-T FH Ability to support multiple operators with the same infrastructure ©Tejas Networks Proprietary & Confidential

©Tejas Networks Proprietary & Confidential Reference CPRI Interface specification http://www.cpri.info/downloads/CPRI_v_6_1_2014-07-01.pdf NGMN Fronthaul Evolution https://www.ngmn.org/uploads/media/NGMN_RANEV_D4_BH_FH_Evolution_V1.01.pdf NGMN Fronthaul Requirements https://www.ngmn.org/uploads/media/NGMN_RANEV_D1_C-RAN_Fronthaul_Requirements_v1.0.pdf ©Tejas Networks Proprietary & Confidential

Jishnu Aravindakshan (Tejas Networks Ltd) jishnu@tejasnetworks.com http://www.tsdsi.org/ THANK YOU Jishnu Aravindakshan (Tejas Networks Ltd) jishnu@tejasnetworks.com