Wi-Fi Wireless Bridging Explained

Wi-Fi range extenders are a variation on bridging

Computer and Cell Phone
  Busakorn Pongparnit/Getty Images 

In computer networking, a bridge joins two networks together so they can communicate with each other and serve as a single network. As Wi-Fi and other wireless networks expanded in popularity, the need to link these networks with one another and with older wired networks increased. Bridges make internetwork connections possible. Wireless bridging technology consists of both hardware and network protocol support.

Types of Wireless Bridges

Hardware that supports wireless network bridging includes:

  • A Wi-Fi to Ethernet bridge is hardware that allows Wi-Fi clients to connect to an Ethernet network. This hardware is integrated with Wi-Fi wireless access points (APs) and is useful with older computers or devices that don't have Wi-Fi capability.
  • A Wi-Fi to Wi-Fi bridge is hardware that joins two Wi-Fi networks together, often to increase the coverage area of a Wi-Fi hotspot. Some wireless AP hardware supports bridging in either Ethernet or Wi-Fi modes.
  • A Bluetooth to Wi-Fi bridge connects devices that communicate with consumer Bluetooth gadgets and interface with a Wi-Fi home network.

Some wireless bridges support only a single point-to-point connection to one other network, while others support point-to-multipoint connections to several networks.

Wi-Fi Bridge Mode

In Wi-Fi networking, bridge mode allows two or more wireless access points to communicate and join their respective local networks. These APs by default connect to an Ethernet LAN. Point-to-multipoint AP models simultaneously support wireless clients while operating in bridging mode, but others can only function point-to-point and disallow any clients from connecting while in bridge-only mode, an option controlled by the network administrator. Some APs only support bridging with other APs from the same manufacturer or product family.

When it is available, AP bridging capability can be enabled or disabled through a configuration option. Normally, APs in bridging mode discover one another via Media Access Control (MAC) addresses that must be set as configuration parameters.

While operating in Wi-Fi bridging mode, wireless APs can generate a substantial amount of network traffic depending on how much cross-network communication is taking place. Wireless clients connected to these APs usually share the same bandwidth as the bridge devices. As a result, client network performance tends to be lower when the AP is in bridging mode.

Wi-Fi Repeater Mode and Wi-Fi Range Extenders

In Wi-Fi, repeater mode is a variation on bridging. Rather than connecting separate networks in a way that allows devices in each one to communicate with each other, repeater mode extends the wireless signal of one network to longer distances for greater reach.

Consumer products called wireless range extenders work as Wi-Fi repeaters, expanding the range of a home network to cover dead spots or areas with weak signal.

Most newer broadband routers are designed to work in repeater mode as an option that the administrator controls. Having the flexibility to choose between full support of a second router and Wi-Fi repeater support is appealing to many households as their home networks continue to grow.