understanding ran.
What is RAN?
Radio Access Networks (RAN) make up the physical components of a cellular network. for the network to work it depends as much on the physical elements as it does the backend elements of the Network Core. RAN is made up of three core elements - Cell sites, Sectors and layers. A RAN network requires the right mix of cell sites, sectors and layers to be able to achieve enough area coverage and customer capacity at any given time.
1.
Cell Sites
2.
sectors
3.
layers
Cell Sites
The cell sites refer to the physical structures that RAN equipment is mounted to (freestanding towers, tall buildings, light poles, etc) and the associated infrastructure
Sectors
A Sector in the RAN is simply a radio & antenna providing coverage to a specific area. As an example, a tower could be placed in the centre of a town, with one radio and antenna positioned to cover the north side of the town and another radio and antenna facing in the opposite direction to cover the south side. This would be defined as having two sectors - they both work in tandem to connect the town to the cellular network, but each sector serves different geographical areas
Layers
Layers in the RAN work by utilising different frequencies to overlap the same area within a cell site so as to give better coverage or increased capacity.
Low band Layers provide excellent coverage over a wide geographical area, however, they are only able to handle small volumes of traffic concurrently.
High band Layers provide less coverage area but have excellent capacity to handle many customers at once.
Midband frequencies are as the name suggests, somewhere in between the two.
An example of additional layers would be a cell site in the middle of the town. The cell site has a low band layer (Layer 1) to service the town and surrounding areas which has great coverage but limited capacity. Adding a mid or high band layer (Layer 2) to the existing cell site allows customers close to the tower to move to this new layer, giving them faster speeds and freeing up capacity on the low-band layer for users further out of town.
