JPL's Wireless Communication Reference Website

Chapter:Cellular Telephone Networks

Cell Sizes

The fact that the user capacity of cellular networks can be increased by reducing cell sizes currently stimulates the development of micro- and pico- cellular networks. In macro-cellular networks cell sizes usually range from 1 to 20 km.

Typically, micro-cellular networks have cell sizes of 400 metres to 2 km, and pico-cellular nets have cell sizes of 4 to 200 metres. For pico- and micro-cellular networks, the name 'personal' communication is often used: most macro-cellular telephone nets are designed for use within cars and may be too bulky and power-consuming to be conveniently portable. With micro- and pico-cellular networks, low transmit powers, say less than 20 mW, can be used, allowing miniaturisation of the handheld terminal.

In summary, we distinguish between

Decreasing cell size gives However, system design differs for macro, micro and pico cells:

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from Short Course by BMRC

Video from Wireless Communications Networks Short Course

"Typical cell sizes for the cellular phone system are one to 30 kilometers with a tendency to go to micro cellular systems. This has several advantages. With an increased user capacity, the transmit power that you have to use in a micro cellular system is also much smaller because the distance that you need to cover is only a few hundred meters so the battery size in your hand held is also smaller. You can have a more convenient device.

There are a lot of other issues, like if you make a cell smaller it is more likely that I move from one cell to another, so it's more likely that the system has to perform a handover to another cell. "

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Hierarchical Cell Structures

To enhance user capacity in so called "hot spots", small microcells can be used to complement macrocells. This leads to a mixed cell structure with macrocells for wide-are coverage and microcells for local capacity. This is often referred to as an Hierarchical Cell Structure. Typically, the operator divides the available spectrum between the two cell layers into a macrocell band and microcell band.

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JPL's Wireless Communication Reference Website 1993, 1995.