What is a backhaul?
In a hierarchical network, a backhaul connects network components from the external part of a network to its internal parts. Backhauls are commonly used in mobile networks to connect base stations to the central system.
What does backhaul mean?
A network that is built in a hierarchical way is split into separate parts. For example, it can be made up of the core network and an access network. A backhaul connects the access network to the core network or to the central network modules. Backhauls technologies vary according to network and network requirements. The term itself does not describe one specific type of technology but refers generally to different types of infrastructure that enable a connection between a central unit in a network and other systems or users within the network. Connections can be wired or wireless.
When and how are backhauls used?
Backhauls have multiple uses in the IT industry. Here are some examples:
- Radio and television broadcasting: the backhaul connects reporters on location with the studio broadcasting the program.
- Base stations in mobile networks: the backhaul creates a connection to the primary base station controller of the mobile network provider.
- Wireless access points: a wireless backhaul connects various local networks with the internet.
Mobile networks are the most common type of network in which a backhaul is used. The term mobile backhaul is often used in this context. This refers specifically to the transfer route from a base station to a core network.
What are different types of backhaul transfer technologies?
Backhaul is a general classification and there are many different connection and transfer technologies used for backhauling.
Transfer technologies have developed over the years. When mobile technology was first introduced, the connection was made on a dedicated line. Depending on the type of line, transfer rates varied between 2 and 34 megabits per second. Due to increased mobile network standards and the need for higher transfer speeds, fibre optic technology is often used today to make connections.
The following transfer technologies can be used to create a backhaul:
- Copper cables
- Fibre optic cables
- Ethernet technology
- Point-to-point radio connections
- Satellite connections
- Passive optical networks (PON)
- Microwave technology
- xDSL technology
A backhaul can be implemented in different types of network topologies. The two methods predominantly used for mobile backhaul implementation are fibre-supported backhauls and wireless point-to-point backhauls. Additionally, ring structures and mesh structures can also function as network topologies. While each of these are solutions in their own right, mobile network providers tend to use a combination of these technologies.
What are common backhaul challenges?
Due to the development of new and more powerful standards in mobile networks, demands on backhauls have increased. More data needs to be transferred at higher rates and with lower latency. As a result, providers need to provide various backhaul connections.
Due to this increase in demand, the trend is to build a larger amount of smaller mobile phone cell towers to increase capacity. This means that backhaul connections represent a massive cost when building and maintaining a mobile network. Additionally, an extremely stable connection is needed to keep network stability high and service requirements low.
Rural areas have their own set of challenges when it comes to creating a quick and reliable mobile network. Compared to urban areas, rural areas have less infrastructure and larger distances that need to be covered. This is why wireless backhaul connections are often used in these areas. Radio communications allows for transfer rates of up to 100 megabits per second. The network carries the signal via radio until it reaches a transfer point, which is connected to the network, for example, via fibre optics.
