Upload
lydang
View
220
Download
2
Embed Size (px)
Citation preview
HFC network introduction and
EPOC requirements from ZSCN
EPOC project team, cable working committee of CRTA
Dongqing Zhang - ZSCN
Guangsheng Wu - Huawei
LinZhi Wang - Broadcom
Mr. Yao Yong – Technical committee of CRTA
1 IEEE P802.3bn> EPoC – October
2012 Additional Interim Meeting
Network Overview
• CATV subscriber number – 0.66M
• Bi-directional covered subscriber number –
0.31M
• Bi-directional penetration ratio is improving.
• Basic topology – Fiber to the residential curb ,
with 1 amplifier and centralized distribution
coaxial cable network.
• Accumulated nearly 10,000 records during per
month test within 3years. User CNR is
maintained at more than 44.5dB.
2 IEEE P802.3bn> EPoC – October
2012 Additional Interim Meeting
EPoC requirements
• Why EPOC?
– Because FTTH is difficult. Zhongshan cable
network is with fiber-to-the residential curb.
– all IP and service development trends
• Spectrum for EPOC
– 5-65MHz and 900-1200MHz
– 5-65MHz spectrum requires to be co-
existence with HPAV EOC.
3 IEEE P802.3bn> EPoC – October
2012 Additional Interim Meeting
Channel test
• Tested at lab environment , with Node+1 topology and
all kinds of tap/splitter/ cable/amplifier
• Selected 2 sites at real network, and tested
noise/interference, etc.
• Mainly tested downstream/upstream Node+1/+0 cable
network characteristics, including signal level, C/N(SNR),
MER, loss - frequency response, group delay, and
calculated micro-reflections accordingly.
4 IEEE P802.3bn> EPoC – October
2012 Additional Interim Meeting
Lab test • Topology
H
L
CATV
HPAV
SP
16
SP
16 30m-9
50m-9
10m-5
S
T
B
• Connected 31 STBs, and separately tested parameters under different conditions, e.g. STB connect/disconnect, STB power on/off.
Test point
SP4
amplifier
SP2
5 IEEE P802.3bn> EPoC – October
2012 Additional Interim Meeting
Network sites
器件箱处需甲方提供220伏不间断电源。
7C-FB电缆线
放大器
二分配器
6C-FB电缆线
四分支器
终端匹配器
图例:
图例:
1/F
初审 制图
图号
图名 4幢楼内系统图
比例 设计 日期 10.7.01
项目
负责
审定
总体负责
校核
项目
2/F
3/F
4/F
5/F
6/F
7/F
8/F
9/F
10/F
11/F
12/F
13/F
14/F
15/F
16/F
9C-FB电缆线
17/F
18/F
豪逸御华庭有线电视工程
20分配
器件箱(55×35×18cm)
分支分配器箱(25×20×10cm)(建设方提供)
过线盒(建设方提供)
金属线槽(100×50mm)(建设方提供)
PVC管1×1Φ 20(建设方提供)
到各户
到各户
到各户
到各户
19/F
20/F
21/F
22/F
23/F
24/F
25/F
到各户
26/F
到各户
20分配
20分配
16分配
2010082-S4
10分配 到商铺
16分配
27/F
28/F
16分配
到各户
到各户
到各户
到各户
到各户
到各户
到各户
到各户
到各户
到各户
到各户
到各户
到各户
到各户
到各户
到各户
到各户
到各户
到各户
到各户
到各户
Test site1
Test site 2 – with HPAV EOC deployed
6 IEEE P802.3bn> EPoC – October
2012 Additional Interim Meeting
CNR test results
Under Node+1 scenario: almost all channels C/N≥43dB.
HPAV EOC signals exist at 5-67MHz spectrum.
All test sites are almost the same, without significant interferences exist.
No freq(MHz) mode power C/N(dB) MER(dB) BER
Z01 112.25 PAL-D -32 45
Z02 120.25 PAL-D -30 43
Z03 128.25 PAL-D -29.3 44.9
DS06 168.25 PAL-D -28.2 47.3
DS08 184.25 PAL-D -28 46.3
Z19 331 64QAM -27 43.3 42 0
Z37 482 64QAM -26 43.4 42 0
DS22 538 64QAM -26.7 42.3 40.7 0
DS23 554 64QAM -26.3 43 41 0
DS25 607.25 PAL-D -24 48.6
DS31 751.18 PAL-D -23.8 48.9
7 IEEE P802.3bn> EPoC – October
2012 Additional Interim Meeting
Below figure shows noise existed below 55MHz, but it was due to
poor connections on a connector of one splitter-16.
If all connectors are well connected, the false noise will disappear.
Poor connection may cause false
noise/interferences.
8 IEEE P802.3bn> EPoC – October
2012 Additional Interim Meeting
The noise floor for both downstream and upstream of N+0 is below
test equipment noise floor (R&S ETL noise floor is about -
165dBm/Hz) , and no significant interferences found.
9 IEEE P802.3bn> EPoC – October
2012 Additional Interim Meeting
Lab test with network analyzer -N+1/+0
N+1 S21 N+1 group delay
N+0 S parameters N+0 group delay 10 IEEE P802.3bn> EPoC – October
2012 Additional Interim Meeting
Real network test –N+0
Test site 1 N+0 S21 Test site 1 N+0 group delay
Test site 2 N+0 S parameters Test site 2 N+0 group delay 11 IEEE P802.3bn> EPoC – October
2012 Additional Interim Meeting
Micro-reflection analysis of test site1
Node+0
• Because all ports of the network are open, without
75ohm terminal match. There exist serious micro-
reflections especially above 1.0GHz frequency.
0 0.2 0.4 0.6 0.8 1 1.2 1.4-60
-50
-40
-30
-20
-10
0Micro reflections 1.0-1.2G
Time (uSec)
Loss(d
B)
0 0.2 0.4 0.6 0.8 1 1.2 1.4-60
-50
-40
-30
-20
-10
0Micro reflections 1.2-1.4GHz
Time (uSec)
Loss(d
B)
12 IEEE P802.3bn> EPoC – October
2012 Additional Interim Meeting
Conclusion
• Under N+0 scenario:
– Given EPOC transmitter power is equal to DVB-C (104dB
μ/8MHz), and the transmission loss is approximately
40dB@860MHz, ≤45dB@1200MHz, and CNU receiver signal
level ≥69dBμ per 8MHz.
– The channel SNR can be higher than 56dB
• Under N+1 scenario: the test SNR is almost higher than
40dB.
• At Zhongshan cable network, with OFDM PHY, the
modulation order can reach 4096QAM
• There are almost no users at two test sites, all network
ports are open, micro-reflections is quite clear.
13 IEEE P802.3bn> EPoC – October
2012 Additional Interim Meeting