Wireless Bridge Vs. Access Point

Wireless bridge and access point offer radio link connectivity over a computer network, but they are structurally and functionally designed to serve slightly different purposes. Setting up a vast wireless network for a corporate office space requires the installation of many networking devices that facilitate connectivity over the entire network. Two such devices are 'Wireless Bridges' and 'Wireless Access Points'. Since both have overlapping areas of functionality, there seems to be confusion regarding how they differ from each other.

Does anyone know the differences between bridges and access points? Are they the same thing? And any info of wireless bridges vs. wireless access points.

Can anybody tell me what the difference between a wireless Bridge and an Access Point?

I am confused in Concepts of Access Point and Wireless Bridges.
What i have figured out is that Wireless bridges relay frames between 802.11 WLAN and 802.3 LAN.
What about AP?

I have a Linksys 10/100 wireless router with several computers connected to it, both wired and wirelessly.

I recently purchased a ReplayTV digital video recorder for my living room, which I attach to my router via an ethernet cable every two weeks to download new program listings from the Internet. I would like to replace this cable with a wireless solution by buying a wiress device and plugging my ReplayTV into it, and having this device give me access to the Internet through my router.

My question is: A) Do I need a wireless access point or a wireless bridge, and B) what's the difference between the two?

All the questions mentioned above show that many network users may be confused with what are wireless bridge and access points, and the main difference between Wireless Bridge and Access Point.

Well, let’s have an overview on wireless bridge and access point, the main features, the main difference…

Wireless Bridges
A computer network tends to be divided into various segments that need to be integrated together. A network bridge connects such divided network segments together, facilitating data sharing. Before the advent of Wi-Fi technology, network bridges were connected through wired ethernet cables. Specifically, in context of the OSI model, network bridges connect segments on layer 2 (data link layer).

These are intelligent devices compared to hubs and repeaters, that control data flow to and fro, from the connected network segments. A wireless bridge performs the same function of linking network segments, but it does that through a Wi-Fi link, instead of a wired ethernet link. It can connect two networks together with a radio link, to facilitate connectivity and data transfer between them.

Such bridges may also be used to connect an ethernet network, with an access point or wireless router, for Internet connectivity. Using a 'Wireless Distribution System', bridges are set up to connect multiple networks. There are more than one types of wireless bridges, ranging from basic ones, which facilitate ethernet connectivity with a wireless access point, to ones that double up as a wireless access point and a bridge. That seems to be the source of confusion between the two devices.

Wireless Access Points
Wireless access points primarily provide Internet access by connecting wireless devices with routers. They act as extenders of a Wi-Fi network, by directly providing Internet access over long distances. Popularly known as 'Wireless Hotspots', they are some of the most widely used networking instruments. Thus a wireless access point provides Internet and LAN connectivity to multiple devices simultaneously.

Some wireless access points also provide the functionality of a wireless bridge, by providing connectivity between two wireless networks. Modern access points can connect more than 200 wireless devices simultaneously. Some wireless access points are in fact wireless routers which directly provide Internet access, through connection with a modem.

Wireless Bridge vs. Access Point

Firstly, look at the simple illustration of wireless bridge and Access Point:

Wireless Bridge 

<Wired LAN>---<Wireless Bridge> ------ <Wireless Bridge>---<Wired LAN>

AP

<Wired LAN>---<AP>----<Wireless Clients>

In the *strict* use of the terminology, the following does NOT work

<Wired LAN>---<AP> ------ <AP>----<Wired LAN>

The AP cannot associate with an AP. 

With that being said, this is usually a software limitation and a lot of AP's can actually function as a bridge.

The central point of difference between the two devices lies in their functionality. While wireless bridges are designed to integrate two physically separated networks through a radio link, an access point connects multiple wireless devices with a router. Thus, a wireless bridge connects two computer clusters together and a wireless bridge connects multiple devices with a single Internet connection simultaneously. A bridge can also be used to connect an existing ethernet network with an access point.

Though wireless bridges and access points were separately manufactured before, today a combination of these two devices is more popularly used. These devices offer both bridging and multiple device wireless connectivity. Therefore, the boundary between the functionality of both devices has become blurred. If you are thinking of buying a wireless access point/bridge device, make sure that you go for a 802.11n wireless networking standard based device, which offers the highest data transmission speed currently.

More Related Wireless Info:

List of Featured Cisco Access Points for Enterprises

http://blog.router-switch.com/2011/11/list-of-featured-cisco-access-points-for-enterprises/

Cisco’s New Aironet Wireless Access Points Make Networks Faster and Steadier

http://blog.router-switch.com/2012/02/cisco%E2%80%99s-new-aironet-wireless-access-points-make-networks-faster-and-steadier/

More general info WIRELESS BRIDGE and ACCESSS POINT

In common wireless usage, a "bridge" is a device which allows for a wireless connection between two physically-isolated wired networks. A wireless LAN bridge can interface an Ethernet network directly to a particular access point. This may be necessary if you have a few devices, possibly in a far reaching part of the facility, that are interconnected via Ethernet. A wireless LAN bridge plugs into this Ethernet network and uses the 802.11 protocol to communicate with an access point that's within range. In this manner, a bridge enables you to wirelessly connect a cluster of users (actually a network) to an access point. Most wireless game adapters are transparent bridges as well.

Access points connect multiple wireless clients to each other and to a wired network. A non-bridging access point will allow association of wireless users, but will generally not allow you to connect to a remote wired network, or to another wireless access point (since they lack a common transparent bridging protocol to replicate the MAC to port table on both ends). Note that there are some access points that can operate in wireless bridge mode as well.

Some access points can also do WDS (wireless distribution system) which can connect to other access points at the same time as client radios. WDS is effectively a store and forward repeater between access points.

A wireless bridge is a hardware component used to connect two or more network segments (LANs or parts of a LAN) which are physically and logically (by protocol) separated. It does not necessarily always need to be a hardware device, as some operating systems (such as Windows, Linux, Mac OS X and FreeBSD) provide software to bridge different protocols. This is seen commonly in protocols over wireless to cable. So in a sense the computer acts as a bridge by using bridging OS software.

Many wireless routers and wireless access points offer either a "bridge" mode or a "repeater" mode, both of which perform a similar common function, the difference being the bridge mode connects two different protocol types and the repeater mode relays the same protocol type. Wireless routers, access points, and bridges are available that are compliant with the IEEE802.11a, b, g and n standards. The frequency bands for these wireless standards can be used license-free in most countries.

Wireless bridge devices work in pairs (point-to-point), one on each side of the "bridge". However, there can be many simultaneous "bridges" using one central device (point to multipoint).

Bridging can be via WDS (Wireless Distribution System) which creates a transparent Level 2 wireless bridge between two or more points. Alternately the bridge can be set up as an access point – client relationship which requires the wireless devices used for the bridge to be set to the same service set identifier (SSID) and radio channel.

An example of a point-to-point bridge application would be connecting two commercial buildings. An example of a combination point-to-point bridge and point to multipoint application would be connecting multiple farm buildings.

Bridging has historically referred to propagation of data across a device without traversing a network stack, such as TCP/IP. Wireless bridging is a colloquial term. A more accurate description of connecting two local area networks would be a Wireless LAN to LAN Bridge. The distinction is important. While a device may not support bridging to a remote wireless access point to connect two LANs, it may be desirable (and supported) that a wireless access point support true bridging; where packets traverse from a wireless to wired network without passing through an internal protocol stack, firewall or other network abstraction. Two bridged networks could be treated as parts of a single subnet under Internet Protocol (IP). A wireless client would be able to make a DHCP request to a wired DHCP server if the wired and wireless networks were bridged. In the ISO OSI model, a device in which packets traverse the network layer is considered a router; a device in which packets traverse the data link layer only is considered a bridge.