11.9 Sector Strategy for Larger Metro Tunnel Projects
It is very important at an early stage to consider the sector plan, cell lay out and capacity for large metro tunnel projects. This will typically be a sub level railway application, and this application will be used as an example in the following chapter. You must make sure to design the cell structure and plan to accommodate current and future needs; typically you will face the challenge of providing a system that can handle 2G, 3G and future services such as LTE, etc. In addition you might have to provide coverage and redundancy for emergency systems.
These, often quite different, systems may not require the same type of strategy or even the same sector plan. At some point there will have to be a compromise where the business case plays a significant part; however, in theory – and often in practice – you can design a cost efficient multi cell/multi operator system with individual sector plans and strategies depending on the service – or in a multi operator scenario, you might have independent sector plans for each of the mobile operators.
So consider carefully the options at an early stage in the design specification of the project; it will often be impossible or unrealistically expensive to make changes to the design or sector plan at a later stage in the process, if it is possible at all.
11.9.1 Common Cell Plans for Large Metro Rail Systems
Let us have a look at some of the more common sector options in large rail tunnel ...