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System Integration
CEM found it difficult to improve CEM's service level to a higher standard without upgrading its legacy communication system
WTT, in partnership with ZTE, provides a total networking solution on optical and Pulse Code Modulation (PCM) layer with full network control using a unified Network Management System (NMS)
Power Up! CEM Completes Optical Transport Network Upgrade

Established in 1972 and serving over 210,000 customers, Companhia de Electricidade de Macau – CEM, S.A. ("CEM") is the only electricity company in Macau. Liberalisation of the gaming industry in 2002 has stimulated urban and economic development in Macau. Land reclamation, construction of glamorous casinos and hotels as well as the changing pattern of the citizens' activities have seen a rapid increase in demand and consumption of electricity for residential and commercial purposes. Consequently, the electricity supply capacity needs to be increased and at the same time the overall quality of power supply improved to cope with Macau's rapid economic development.

"CEM's total gross electricity consumption reached 3,654 GWh in 2009, almost double that of 2002. Our system average interruption duration index (SAIDI) was kept to an excellent 5.51 minutes in 2009," said Benjamin Yue, Senior Manager of Power and Networks Dispatch Department (PND) of CEM. "In view of the second wave of rapid growth of Macau, the legacy pilot cable-based communication system needs to be improved to secure premium power supply quality with a much more robust and reliable communication infrastructure. We want to upgrade our optical transport and distribution network so that we have centralised management control to monitor and control the power system."

Locating qualified vendor

CEM was very prudent in selecting the qualified service provider to manage CEM's optical transport network upgrade. It must possess a proven track record in network design and project management, sophisticated knowledge in SDH network implementation, a strong financial background, relevant experience in the utility sector, and above all, the ability to provide total solutions for network and IT management. WTT is their best choice of service partner.

WTT clearly understood CEM's particular requirements and selected ZTE's S325 Compact Multi-Service Node Equipment and S200 Integrated Access Device Node to provide secure and reliable communication between 25 CEM Transmission Substations through multiple SDH STM-1 (Synchronous Transport Module-1) and STM-4 rings on optical layer. SDH (Synchronous Digital Hierarchy) is a standard transmission protocol for fibre optic networks that provides high communication capacity and excellent protection against damage to the fibre. A core fibre backbone network was designed to geographically connect the Macau peninsular to Taipa and Coloane. In addition to an intra-network in Macau, an external optical connection was set up for the 220kV interconnection between Zhuhai and Macau.

All of CEM's substations are fully automated and monitored by the centralised Supervisory Control and Data Acquisition (SCADA) system as well as on-site Remote Terminal Units (RTU). All the SCADA signals and the analogue telephone interfaces on all 25 substations are managed using the Pulse Code Modulation (PCM) layer through the ZTE BX10E connecting to SDH optical nodes. Finally, a unified Network Management System (NMS) has been set up to exercise single and overall control of the network on both optical and PCM layer by implementing the ZXONM E300 Element Management System.

Considerable improvement on security, manageability and scalability

The new solution has built-in spare capacity growth with at least 25% of the channels being spare while the platform can be upgraded easily to cater for 500% to 1000% of the existing required bandwidth. The automatic report generating function facilitates detailed analysis of current and past alarm and event reports, therefore tightening centralised control on capacity usage and distribution/transmission management.

Multiple network resilience and a high degree of protection have been achieved with the newly enhanced optical transport network. All locations now have two separate optical paths (East and West) with 50ms time recovery in case of SDM interface or fibre failure. The Automatic Laser Shutdown (ASL) and Automatic Protection Switching (APS) functions of S325 optical interfaces offer additional safety measures during circuit break and loop data into protection route within 50ms to provide network self healing. The unified Network Management System (NMS) provides advanced architecture and higher flexibility. Moreover, its multi-process design approach means the system can process several tasks simultaneously.

"During project implementation, WTT demonstrated their ability to manage projects by prioritising the implementation schedule effectively, keeping close control of progress and reporting abnormal incidents instantly for immediate arrangement," said Charles Leong, Project Manager, System Dispatch Engineering Unit Manager of PND, CEM. "We appreciate WTT's strong initiative and great team spirit that successfully drove the project. Their proactive request to initiate the network design workshop during the planning stage has helped CEM identify critical elements for maintaining exceptional network manageability, scalability and reliability. Their full team support allows us to focus our resources on inter-connection project management."

The project was completed in March 2009 and WTT will continue to provide CEM with technical support. "Communication quality of the overall power system in both our Transmission and Distribution Networks has improved enormously. It facilitates continuous development of our power system and sustainability of the Macau community," commented Charles Leong.

Fuelling Macau's Growth

In addition to the network upgrade project, CEM has embarked on a series of investments in transmission and distribution projects to cope with Macau's rapid economic development. In 2009, CEM invested over MOP 806 million in the network infrastructure to improve power reliability, including the second inter-connection with Guangdong Power Grid and the 220kV Backbone inter-connection projects. "CEM fully recognises its role and responsibility in creating sustainable value for its stakeholders and is committed to building a sustainable and environmentally friendly future for Macau," Benjamin Yue noted. "We will continue to enhance our operation standards to provide a first-class service to the Macau community."