Wi-Fi Wireless Bridging Explained

In computer networking, a bridge joins two networks together. As Wi-Fi and other wireless networks expanded in popularity, the need to link these networks with each other and with older wired networks has also increased. Bridges makes these inter-network connections possible. Wireless bridging technology consists of both hardware and network protocol support.

Types of Wireless Bridges

Several different forms of hardware have been developed to support wireless network bridging including:

• Wi-Fi to Ethernet: Hardware that allows Wi-Fi clients to connect to an Ethernet network. This hardware is integrated with Wi-Fi wireless access points (APs).
• Wi-Fi to Wi-Fi: Hardware that joins two Wi-Fi networks together, often for the purpose of increasing the coverage area of a Wi-Fi hotspot. Some wireless AP hardware supports bridging in either Ethernet or Wi-FI modes.
• Bluetooth to Wi-Fi: Bridge 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 APs to communicate with each and join their respective local networks together. 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 furthermore only support bridging with other APs from the same manufacturer or product family.

AP bridging capability (when it is available) can be enabled or disabled through a configuration option. Normally, APs in bridging mode discover each other 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 happening. Wireless clients connected to these APs generally share the same bandwidth as the bridge devices. Therefore, 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 simply extends the wireless signal of one network out 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 have also been built to work in repeater mode as an option controlled by the administrator. Having the flexibility to choose between full support of a second router and Wi-Fi repeater only support is appealing to many households as their home networks continue to grow.