PTCL: Building a Sustainable Optical Network

Pakistan Telecommunication Company Limited (PTCL), which is a subsidiary of Etisalat, is Pakistan’s largest fixed-line network and broadband operator. With over 30 million users, its core businesses include the fixed-line network, CDMA WLL, data, and value-added services. Its fixed-line network share accounts for 97 per cent, ranking first in Pakistan and its subsidiary (UFone) occupies a large share in Pakistan’s mobile market. In recent years, due to the deployment of LTE/EV-DO and the expansion of nationwide broadband services, the bandwidth demand for PTCL’s bearer network is sharply increasing, causing a heavy stress on network bandwidth.

PTCL’s backbone DWDM network has dual planes. One of the planes was constructed in 2007, and the network capacity is a 40-wavelength 10G system. However, the increased bandwidth saturated the network capacity. On the premise of protecting the investment of the existing network, improve the network capacity and complete the project efficiently are PTCL’s priorities for network reconstruction in 2014.

 

The competition in Pakistan is fierce. PTCL’s DWDM network involves two planes. Early in 2013, when PTCL had no specific project requirements, ZTE already predicted that PTCL would require large bearer bandwidth in 2014 as the 4G network, IDC network, and smart IPTV services evolved rapidly. ZTE then organized a network optimization team and proposed two upgrade solutions. In Solution 1, the existing network was upgraded to 80-wavelength 10G/100G system, and 10G channels were added (in the future, 100G channels can be added as required). In Solution 2, 100G-wavelength was added to the 10G network directly. Therefore, when PTCL explicitly required upgrading its bearer network in 2014, ZTE’s professional solutions satisfied PTCL very much.

 

Solution Optimization to Reduce CAPEX and OPEX

Considering the investment and sustainable development, PTCL preferred Solution 1, so ZTE optimized solution 1 to reduce CAPEX and OPEX, and build a green network.
For the old DWDM devices in more than 100 sites of the existing network, some magnified boards were replaced to enhance the network OSNR performance. After the system is upgraded to 80-wavelength, the minimum number of trunk boards was used to guarantee a low CAPEX of the entire network.
New ZXONE 8000 devices were connected to old ones of the existing network, and the new service boards were added to the new devices. In the wave-division project, most of investment was put in service boards. Compared with the 10G service boards in the existing network, the new 10G service boards of ZXONE 8000 boasted a low cost and better performance, thus greatly reducing the CAPEX of capacity expansion.
In addition, the newly introduced 10G board was half size of the original board, and the number of service slots in a new subrack was larger than that of the original one. These reduced the equipment room space and OPEX as well.
Furthermore, a new compatible service board was introduced to improve the flexibility of wavelength scheduling and reduced OPEX.
The optimized network could be smoothly upgraded to 100G and even beyond 100G for sustainable development.

Fast and Highly Efficient System Delivery

Due to a rather short construction period, before the devices arrived, ZTE’s engineering team had deployed U31 network management servers in the Pakistan site to upgrade the network management system (NMS). After the devices arrived, all hardware components were installed, some old OA boards were replaced, the capacity for new services was expanded, and trunk boards were added. Most of services adopted OP multi-path protection, which ensured the fastest project commissioning and the least interference to provisioned services.
During PTCL’s backbone DWDM network capacity expansion project, it took only two months to complete contract sending, scheduling, and device delivery, and took six months to fulfill the upgrade, reconstruction and service provisioning. The network has been commercialized at the end of 2014, which guarantees PTCL’s bandwidth demands for smart TV and 4G services. ZTE also won high praise from PTCL.

 

Smoothly Upgraded Green Bearer Network

With 30 years of experience in the telecom industry, ZTE successfully upgraded PTCL’s network from 40-wavelength to 80-wavelength, and achieved fast network commissioning. This not only protected PTCL’s investments, but also reduced the CAPEX and OPEX of its network. In the future, the advanced 100G technology, beyond 100G technology, and OTN electrical cross platform can be introduced to build a sustainable network.
●    Smooth upgrade. ZXONE 8000 platform is introduced to smoothly upgrade to 100G or beyond 100G capacity. The transponder or muxponder services can be implemented through adding service boards. While the OTN cross platform can be implemented through adding proper OTN cross platforms and service boards. The introduction of new services does not affect provisioned services.
●    Superior performance. The OTN platform has the largest cross capacity and the maximum number of slots, supporting an upgrade to 100G or 400G. It adopted the most advanced SD-FEC technology, and has the most powerful 100G transmission capability. For 100G, which adopted the leading DSP technology, the dispersion tolerance is ±70000 ps/nm, and the PMD tolerance is 60 ps. In addition, 100G supports the trunk long-distance transmission without electrical regeneration (more than 5000 kms), the mixed convergence of STM-N/GE/10G/40G services in any granularity, and ODU0/1/2/2e/3/4/flex crossing, meeting different application scenario requirements of operators.
●    Environmental protection. As the advanced 28 nm processing AISC chip is applied, the 100G board significantly reduces heat dissipation and power consumption of the PCB. The advanced mechanical and electrical management mechanism is introduced to allow circuits and optical modules to enter dormancy mode, which reduces the power consumption of idle modules. The super high-precision temperature measurement and intelligent heat dissipation system can adjust the fan speed in real time according to the measured temperature. In this way, the system operating temperature can be reduced maximally while the energy consumption of fans can be controlled.