Final Report Name of Networks Backbone Network Core Network Metro Network Chapter 5 Mid-Term Development Plan Table 5.2-1 Outlines of Junction Networks Outlines . Backbone circuits connecting three big cities Yangon, Naypyitaw and Mandalay . At present, connection is made through microwave radio links and fiber optic cable links . Communication paths connecting all cities in the countries including backbone networks. . At present the microwave radio links are used mainly. . Loop networks connecting exchanges within the cities . At present, the networks are provided in Yangon, Naypyitaw and Mandalay metropolitan areas. . At present, the fiber optic cable links are provided. Source: Prepared by the Survey Team. 5.2.2 Backbone Network (1) Present Status and Subject To be solved The backbone networks connecting main cities, Yangon, Naypyitaw and Mandalay are provided through the microwave radio links and the fiber optic cable links at present. Installation and the maintenance and control are provided by Long Distance Communications at present. The microwave radio links are provided over three routes, i.e., the western route, the central route and the eastern route. In the western route are provided the oldest system. The capacity is 126E1 (252Mbps) in which 63E1 (126Mbps) is branched at every repeater stations, and connected to the subscriber exchanges. The remaining 63E1 (126Mbps) from Yangon are passes each repeater stations and reaches to Mandalay. The frequencies used are in 6GHz band and 9GHz band (Sub), therefore no influences through rainfalls, however, there remains some problems in lack of spare parts, therefore there remains drops of the reliability of the equipment. The actual route is indicated by the red dotted lines in Figure 5.2-1. The transmission capacity of the central route is 1.2Gbps and operated at IP+64E1 (128Mbps) at present. The frequency used are from 6GHz band. This route are shown in blue color and the Figure 5.2-1 The eastern route gives the capacity of 1.2Gbps and is operated in IP+64E1 (128Mbps). The radio frequency used is from 11 GHz, that is easily affected by rain falls, it is operated in 64E1 (128Mbps), because the band of 1.2Gbps could not be maintained continuously. This route is shown in green color in the figure. The repeater station in the Eastern route utilizes commonly the repeater stations of the fiber optic cable link. This route is shown in green color in the Figure 5.2-1. The fiber-optic cable link are provided along the national road (Route A in the Figure 5.2-2) and along the high way (Route B in the Figure 5.2-2). Along the national road, 12-shin cables are buried. The existing wave-length division multiplex equipment (WDM) used are made in Huawei (China) or Optelian (Canada), and occupy bandwidth, IP20Gbps + 16STM1 (16X155Mbps), and IP10Gbps+64STM1 (64X155Mbps), respectively. At present, the Optelian is on the way to 5-3