Medalas Presentation of Network Optimisation problems, given at the TETRA Association China Roadshow in October 2010 in Hangzhou, Guangzhou and Chengdu

1. Maximising Your TETRA N etwork Investment 使您的 TETRA 网络投资发挥最大作用

12. Cell Dragging - 1 In this example a drive test measured the same location twice from different directions – from one direction receiving very good service, and from the other direction receiving very poor service – very confusing to users 在这一例子中，通过路测从不同的方向对同一地点进行了两次测试——一个方向接收到了非常好的服务，而另一个方向接收到了非常差的服务——用户对此非常困惑 Cell 5 0 to -9 dBm -10 to -19 dBm -20 to -29 dBm -30 to -39 dBm -40 to -49 dBm -50 to -59 dBm -60 to -69 dBm -70 to -79 dBm -80 to -89 dBm -90 to -99 dBm -100 to -109 dBm -110 to -119 dBm

13. Cell Dragging - 2 The problem started here, with the handset attached to cell 1 问题由连接到小区 1 的对讲机设备开始 Cell 1 Cell 2 Cell 5 0 to -9 dBm -10 to -19 dBm -20 to -29 dBm -30 to -39 dBm -40 to -49 dBm -50 to -59 dBm -60 to -69 dBm -70 to -79 dBm -80 to -89 dBm -90 to -99 dBm -100 to -109 dBm -110 to -119 dBm Cell 4 Cell 3

14. Cell Dragging - 3 At this point the handset moves to cell 2 – a good choice 在这一地点，对讲机移动到了小区 2 —— 非常好的选择 Cell 1 Cell 2 Cell 5 0 to -9 dBm -10 to -19 dBm -20 to -29 dBm -30 to -39 dBm -40 to -49 dBm -50 to -59 dBm -60 to -69 dBm -70 to -79 dBm -80 to -89 dBm -90 to -99 dBm -100 to -109 dBm -110 to -119 dBm Cell 4 Cell 3

15. Cell Dragging - 4 But the problems start here, because cell 2 should be broadcasting cell 5 as a neighbour cell, and in this example was not – very bad 但是问题由此开始，因为小区 2 应该广播 cell5 为相邻小区，但是在这一例子中却没有发生——非常糟糕 Cell 1 Cell 2 Cell 5 0 to -9 dBm -10 to -19 dBm -20 to -29 dBm -30 to -39 dBm -40 to -49 dBm -50 to -59 dBm -60 to -69 dBm -70 to -79 dBm -80 to -89 dBm -90 to -99 dBm -100 to -109 dBm -110 to -119 dBm Cell 4 Cell 3

16. Cell Dragging - 5 This means that the radio handset is now travelling towards cell 5, but has no knowledge of its existence – it relies on the network to give it correct information about the cells around it 也就是说，无线电对讲机现在向小区 5 移动，但是却没有意识到它的存在——这依赖于网络能够向它提供关于周围小区的正确信息 Cell 1 Cell 2 Cell 5 0 to -9 dBm -10 to -19 dBm -20 to -29 dBm -30 to -39 dBm -40 to -49 dBm -50 to -59 dBm -60 to -69 dBm -70 to -79 dBm -80 to -89 dBm -90 to -99 dBm -100 to -109 dBm -110 to -119 dBm Cell 4 Cell 3

17. Cell Dragging - 6 At this point the radio handset is getting a poor signal from cell 2 so decides to move back to cell 1 – moving to cell that the handset is travelling away from is often a sign of a problem 在这一地点，无线电对讲机从小区 2 接收到了很差的信号，因此决定回到小区 1 —— 向无线电设备正在离开的小区移动，这经常是出现问题的信号 Cell 1 Cell 2 Cell 5 0 to -9 dBm -10 to -19 dBm -20 to -29 dBm -30 to -39 dBm -40 to -49 dBm -50 to -59 dBm -60 to -69 dBm -70 to -79 dBm -80 to -89 dBm -90 to -99 dBm -100 to -109 dBm -110 to -119 dBm Cell 4 Cell 3

18. Cell Dragging - 7 Because the decision to move back to cell 1 is a bad one, after 30 seconds the radio handset has to move cell again – this time it makes another bad decision due to the lack of information from the network – it moves to a cell that is more than 30Km away – it moves to cell 3 因为返回小区 1 是一个错误的决定，所以 30 秒之后，无线电对讲机必须再一次离开这个小区——这一次，它会因为缺少由网络而来的信息而做出另一个错误的决定——它移动到了另一个 30 千米之外的小区里——它移动到了小区 3 Cell 1 Cell 2 Cell 5 0 to -9 dBm -10 to -19 dBm -20 to -29 dBm -30 to -39 dBm -40 to -49 dBm -50 to -59 dBm -60 to -69 dBm -70 to -79 dBm -80 to -89 dBm -90 to -99 dBm -100 to -109 dBm -110 to -119 dBm Cell 4 Cell 3

19. Cell Dragging - 8 Now on cell 3 – the radio handset it being told about neighbour cells for cell 3 – which are not correct for the real location of the radio handset 现在在小区 3 中——无线电对讲机被告知小区 3 为相邻小区——这对无线电对讲机的真实地点来说是不正确的 Cell 1 Cell 2 Cell 5 0 to -9 dBm -10 to -19 dBm -20 to -29 dBm -30 to -39 dBm -40 to -49 dBm -50 to -59 dBm -60 to -69 dBm -70 to -79 dBm -80 to -89 dBm -90 to -99 dBm -100 to -109 dBm -110 to -119 dBm Cell 4 Cell 3

20. Cell Dragging - 9 At this point service delivered to the user is seriously reduced for several kilometres, the signal strength less than -100dBm as shown by the red and purple circles, and experienced failed calls and poor speech quality 在这一地点，几千公里内，为用户提供的服务质量严重下降，如红色及紫色圆圈所示，信号强度低于 - 100dBm ，通话故障并且语音质量很差 Cell 1 Cell 2 Cell 5 0 to -9 dBm -10 to -19 dBm -20 to -29 dBm -30 to -39 dBm -40 to -49 dBm -50 to -59 dBm -60 to -69 dBm -70 to -79 dBm -80 to -89 dBm -90 to -99 dBm -100 to -109 dBm -110 to -119 dBm Cell 4 Cell 3

21. Cell Dragging - 10 The radio handset then makes another attempt to find good service and this time moves to cell 4 as a result of losing service and scanning all frequencies 由于失去了服务，在对所有的频率进行扫描后，无线电对讲机又一次尝试寻找良好的服务，这一次它移动到小区 4 Cell 1 Cell 2 Cell 5 0 to -9 dBm -10 to -19 dBm -20 to -29 dBm -30 to -39 dBm -40 to -49 dBm -50 to -59 dBm -60 to -69 dBm -70 to -79 dBm -80 to -89 dBm -90 to -99 dBm -100 to -109 dBm -110 to -119 dBm Cell 4 Cell 3

22. Cell Dragging - 11 The final problem is with cell 4 – it should be broadcasting cell 5 as a neighbour, but is not transmitting any neighbour cell information at all 最后的问题与小区 4 有关——原本它应广播小区 5 为相邻小区，但是却没有发送任何相邻小区的信息 Cell 1 Cell 2 Cell 5 0 to -9 dBm -10 to -19 dBm -20 to -29 dBm -30 to -39 dBm -40 to -49 dBm -50 to -59 dBm -60 to -69 dBm -70 to -79 dBm -80 to -89 dBm -90 to -99 dBm -100 to -109 dBm -110 to -119 dBm Cell 4 Cell 3

23. Cell Dragging - 12 This means that the only way for the handset to move from this cell is to reach the point where service is lost completely and a new scan can be performed to find a usable cell 也就是说，对讲机从这一小区移出的唯一途径是到达一个完全丧失了服务并且可以通过新的扫描找到一个有可用小区的地点 Cell 1 Cell 2 Cell 5 0 to -9 dBm -10 to -19 dBm -20 to -29 dBm -30 to -39 dBm -40 to -49 dBm -50 to -59 dBm -60 to -69 dBm -70 to -79 dBm -80 to -89 dBm -90 to -99 dBm -100 to -109 dBm -110 to -119 dBm Cell 4 Cell 3

24. Cell Dragging - 13 The result of this sequence of poor configuration optimisation is that at the same point on this road users receive very different service depending upon the direction of travel 对较差的配置进行一系列优化的结果是，在一条路上相同的地点，用户接收到不同的服务取决于移动的方向不同 Cell 5 0 to -9 dBm -10 to -19 dBm -20 to -29 dBm -30 to -39 dBm -40 to -49 dBm -50 to -59 dBm -60 to -69 dBm -70 to -79 dBm -80 to -89 dBm -90 to -99 dBm -100 to -109 dBm -110 to -119 dBm

25. Cell Dragging - 14 Travelling from south to north on this road at this point when on the correct cell for the location – the radio handset is receiving a very strong signal of -44dBm 从南向北移动到这条路的这个地点，当它在这个地点的正确的小区时——无线电对讲机可以接收到高达 -44dBm 信号强度的信号 Cell 5 0 to -9 dBm -10 to -19 dBm -20 to -29 dBm -30 to -39 dBm -40 to -49 dBm -50 to -59 dBm -60 to -69 dBm -70 to -79 dBm -80 to -89 dBm -90 to -99 dBm -100 to -109 dBm -110 to -119 dBm

26. Cell Dragging - 15 Travelling from west to east on this road at this point when on the incorrect cell for the location – the radio handset is receiving a very poor signal of -100dBm 从西向东移动到这条路的这个地点时，当它在这个地点的不正确的小区时——无线电对讲机会接收到信号强度为 -100dBm 的非常差的信号 Cell 5 0 to -9 dBm -10 to -19 dBm -20 to -29 dBm -30 to -39 dBm -40 to -49 dBm -50 to -59 dBm -60 to -69 dBm -70 to -79 dBm -80 to -89 dBm -90 to -99 dBm -100 to -109 dBm -110 to -119 dBm

27. Cell Dragging - 16 The result – sometimes very good service and sometimes very bad service – very confusing for users – they almost always report it as a “coverage problem” when in fact it is a simple matter of optimisation 结果是——有的时候服务质量非常好而有的时候服务质量非常差——用户对此非常困惑——他们几乎总是会将其报告为覆盖范围问题，而事实上，这只是一个简单的优化问题 Cell 5 0 to -9 dBm -10 to -19 dBm -20 to -29 dBm -30 to -39 dBm -40 to -49 dBm -50 to -59 dBm -60 to -69 dBm -70 to -79 dBm -80 to -89 dBm -90 to -99 dBm -100 to -109 dBm -110 to -119 dBm