With the dramatic IP and mobile data growth, the carriers deploy more and more BBU and RRU to extend the mobile network coverage and improve the customer experience. At the same time, the centralized deployment of BBU and the rapid increase of RRU put forward higher requirements for manpower, land, fiber optic cable resources, etc.
♢ The optical connection between a standard RRU group and BBU requires 6 fibers. The fiber quantity in some co-constructed station reaches 12/18 cores. The increasing of BTS and RRU causes the integer multiple increase of BBU fiber cables.
♢ One-to-One fiber connection mode between BBU and RRU has many problems, such as long construction cycle, high cost and many restrictions. It is not the most time saving and cost saving C-RAN fronthaul solution.
Therefore, fiber capacity expansion is the most effective way to solve the surge in demand for fiber optic resources in C-RAN fronthaul applications. We introduce the following several fiber capacity expansion solutions for C-RAN fronthaul applications.
Summary
In C-RAN, BTS are widely deployed in different sites with multiple installation conditions. Fiber capacity expansion solutions in C-RAN need fulfill the following requirements:
1. Maximumly keep the original network structure;
2. Workers can master the installation process in a short time;
3. Multiple-scenario solutions for different BTS conditions;
4. Line protection for critical BTS;
Introduction
According to different conditions such as hardware situations, fiber cable resources and project budgets, we provide four fiber capacity expansion solutions for C-RAN fronthaul applications, the user can choose the best fit one according to the actual conditions.
|
No. |
C-RAN Scenario |
Solution |
|
1 |
No more than 9 RRU in one BTS |
Ø Passive CWDM MUX Ø Active WDM Platform Ø Passive Single Double Unit Ø Single-Fiber BIDI Optical Transceiver |
|
2 |
No replacement of RRU optical transceiver |
Ø Active WDM Platform Ø Passive Single Double Unit |
|
3 |
Mostly save fiber resource |
Ø Passive CWDM MUX Ø Active WDM Platform |
|
4 |
Monitor and protection of BBU-RRU optical lines |
Ø Active WDM Platform |
|
5 |
Least cost |
Ø Single-Fiber BIDI Optical Transceiver |
Solution 1: Passive CWDM MUX
In this solution, OTP5300 passive CWDM MUX is deployed in both BBU and RRU sides. The original white light optical transceivers of BBU and RRU should be replace with CWDM optical transceivers with different wavelengths. This solution can combine 6/12/18 fiber channels into 1~2 fibers to save fiber resources between BBU and RRU. Single or double fibers are optional for trunk fiber link.
Features
◇ Convenient
♢ Passive without power supply, plug and play, short construction period
♢ Pure passive optical device, low failure rate
◇ Multi Scenarios
♢ Multiple types for different scenarios;
♢ Low insertion loss solution is available for 8-channel above applications;
♢ No pigtail low insertion loss solution is available for optical dispatch box application
◇ Flexible
♢ Star, linear topology, high integrated;
♢ Optional single or dual core for trunk optical link. Maximum 18 channels in a single fiber;
♢ Expansion port for channel quantity expansion
Product List
|
Product |
Description |
|
OTP5300 |
Passive CWDM MUX, 6/12/18 channels, Optional single or dual core for trunk optical link, available for the installation in cabinet, outdoor pole/wall mounting waterproof boxes |
|
CWDM Optical Transceiver |
Wavelength range 1271nm~1611nm, 1.25G/2.5G types always for 3G and 10G types for 4G. 5~8km, 5~35km transmission distance |
Solution 2: Passive Single Double Unit
In this solution, a pair of PSDU are deployed between each BBU-RRU link, to convert the original dual fiber transmission into a single fiber transmission, and to reduce the fibers occupation from 6 to 3 between BBU room and the BTS without any change of the original BBU and RRU equipment.
Features
◇ Convenient
♢ Passive, plug and play;
♢ Small size, easy installation and maintenance
◇ Flexible
♢ Transparent data transmission, compatible with any data rate;
♢ Available for both 1310nm and 1550nm signals
◇ High Quality
♢ Low insertion loss, low polarization sensitivity, high isolation, high return loss. for high transmission quality
Product List
|
Product |
Description |
|
ODTS5200 |
Passive Single Double Unit (PSDU), realize the single/double fiber transformation for bi-directional 1310nm or 1550nm optical transmission, optional LC/SC connector |
Solution 3: Active WDM Platform
In this solution, OTP5500 active WDM platform is deployed in both BBU and RRU sides for wavelength conversion, signal amplifying and optical channel MUX/DEMUX processing without any change of the original BBU and RRU equipment. This solution can combine 6/12/18 fiber channels into 1~2 fibers to save fiber resources between BBU and RRU. 1+1 or 1:1 protection is available for trunk fiber link.
Features
◇ Multi-function
♢ Support wavelength conversion, MUX/DEMUX, etc.;
♢ High fiber utilization without changing original equipment.
◇ Convenient
♢ Multiple types for different scenarios;
♢ Support CPRI data rate (9.8G/6.14G/4.9G/2.45G/1.22G) in one platform
◇ Reliable
♢ 1+1 or 1:1 protection for trunk fiber link;
♢ SNMP management with GUI, low OPEX
Product List
|
Product |
Description |
|
OTP5500 |
Active WDM platform, 19” 1U/2U/5U chassis, outdoor type is optional |
|
OTP5500-8*10G |
OEO repeater card for OTP5500 chassis, support wavelength conversions of 4 lines of optical signals. 10G data rate downward compatible for 1.25G/2.5G/10G optical transceivers |
|
OTP5500-OMUX |
CWDMMUX/DEMUX card for OTP5500 chassis, support 6/12/18 channels, optional 1 or 2 fibers for optical trunk link |
|
CWDM Optical Transceiver |
CWDM optical transceiver, 1271nm~1611nm, 1.25G/2.5G types always for 3G and 10G types for 4G, 5~8km, 5~35km transmission distance |
Solution 4: Single-Fiber BIDI Optical Transceiver
In this solution, the original dual-fiber optical transceivers of BBU and RRU are replace with single-fiber BIDI optical transceivers, to reduce half of the fibers occupation from 6 to 3 between BBU room and the BTS without any change of the original BBU and RRU equipment.
Features
◇ Convenient
♢ One-to-one replacement of normal white color optical transceivers;
♢ Plug and play for fast installation
◇ Low Cost
♢ Add no extra equipment, only the replacement of optical transceivers
◇ Reliable
♢ No new optical connection node
Product List
|
Product |
Description |
|
Single-Fiber BIDI Optical Transceiver |
Single fiber, single mode, 1310nm/1550nm, 1.25G/2.5G/10Gbps optional, 10km, 20km, 40km transmission distance |
