What Is a Wireless Access Point?

A wireless access point is a device that adds Wi-Fi to a wired network by bridging wireless clients onto the wired LAN. A wireless access point connects to a switch or router with an Ethernet cable and broadcasts a Wi-Fi signal that phones, laptops, and other wireless devices join. This article defines a wireless access point, explains how an access point bridges wireless and wired traffic, compares an access point against a router, and states when standalone access points are used.

A wireless access point operates on the IEEE 802.11 family of standards, the same standards that define Wi-Fi. An access point does not assign IP addresses and does not route traffic between networks, so an access point depends on a router and a switch already present on the network. The sections below cover the access point definition, how an access point works, access point versus router, standalone versus built-in access points, multiple access points and roaming, and how an access point compares with a mesh network.

What Is a Wireless Access Point?

A wireless access point is a device that provides Wi-Fi access to a wired network by bridging wireless clients onto the wired LAN. A wireless access point connects to a switch or router by Ethernet cable and converts wired traffic into a wireless signal and back.

A wireless access point operates on the IEEE 802.11 standards, which define the Wi-Fi physical and data link behavior across versions such as 802.11ac and 802.11ax. An access point extends an existing network rather than creating one, because an access point holds no routing function and assigns no addresses. The wired network an access point joins is built from a network switch and a router, and the access point adds the wireless layer on top.

How Does a Wireless Access Point Work?

A wireless access point works by converting Ethernet frames from the wired network into 802.11 wireless frames and broadcasting them to wireless clients. An access point acts as a bridge between the wired medium and the radio medium.

The operation of a wireless access point follows three steps listed below. Each step describes one part of how an access point moves traffic between the wired LAN and wireless devices.

• Connects to the wired network. An access point links to a switch or router port by Ethernet cable, often powered through the same cable using Power over Ethernet defined in IEEE 802.3af.
• Broadcasts a wireless network. An access point advertises a network name, the SSID, on the 2.4 GHz and 5 GHz bands so wireless clients can find and join the network.
• Bridges traffic both ways. An access point converts each wired frame into an 802.11 frame for the air and converts each received wireless frame back into an Ethernet frame for the wired LAN.

A wireless access point passes the IP addressing job to the router, so the router still assigns each wireless client an address through DHCP. The access point handles only the radio link and the bridge, which is the basis of how Wi-Fi reaches a wired network as explained in what Wi-Fi is.

What Is the Difference Between an Access Point and a Router?

An access point only adds Wi-Fi to an existing network, while a router connects networks and assigns IP addresses. An access point operates at layer 2 as a bridge, and a router operates at layer 3 to route packets between networks.

The comparison table below lists how a wireless access point and a router differ across the attributes that define each device.

A wireless access point depends on a router to function, because the access point bridges clients onto a network the router already created. A router can include an access point inside its case, but a standalone access point performs only the wireless bridge. The difference between routing and switching that underlies this split is covered in the comparison of a switch and a router.

What Is the Difference Between a Standalone and a Built-In Access Point?

A standalone access point is a separate device that adds Wi-Fi to a wired network, while a built-in access point is the wireless section inside a home router. The distinction rests on whether the access point ships as its own unit or as part of a router.

• Built-in access point. A home router contains an access point alongside its router and switch sections, so a single home router provides routing, wired ports, and Wi-Fi from one unit.
• Standalone access point. A standalone access point is a dedicated device that connects to a switch or router by Ethernet and serves only as the wireless bridge, often mounted on a ceiling for even coverage.
• Controller-managed access point. A standalone access point in a business network often reports to a central controller that manages many access points under one configuration.

A built-in access point suits a small home where one unit covers the whole space, while a standalone access point suits a larger area where one router cannot reach every room. The role of the router that hosts the built-in access point appears in the overview of what a router is.

How Do Multiple Access Points and Roaming Work?

Multiple access points extend Wi-Fi across a large area, and roaming lets a device move between access points without dropping the connection. Several access points share one network name so devices treat the area as a single wireless network.

Three settings make multiple access points work as one network. Each setting controls part of how devices move between access points.

• Share one SSID. Each access point broadcasts the same network name, so a device sees one network and connects to whichever access point gives the strongest signal.
• Use separate channels. Neighboring access points use different channels on the 2.4 GHz and 5 GHz bands to avoid interference between overlapping coverage areas.
• Support roaming standards. Access points that support IEEE 802.11r speed up the handoff so a device switches access points with little interruption to a call or stream.

A device decides when to roam based on signal strength, then reassociates with a closer access point. Wiring several access points across a building is part of the work covered in the guide to improve a Wi-Fi signal.

What Is the Difference Between an Access Point and a Mesh Network?

An access point connects to the network by Ethernet cable, while a mesh network links its nodes wirelessly to each other. Both extend Wi-Fi coverage, but each uses a different backhaul to reach the main network.

• Wired access points. Each access point runs an Ethernet cable back to the switch or router, which gives full wired speed to every coverage point but requires cabling to each location.
• Wireless mesh nodes. Each mesh node connects to other nodes over a wireless backhaul, which avoids cabling but shares radio bandwidth between the backhaul and the clients.
• Coverage versus cabling. A wired access point setup suits buildings with existing Ethernet runs, while a mesh suits homes where running cable is impractical.

A mesh network trades some throughput for easy installation, while wired access points keep full speed at the cost of cabling. The full design and node behavior of a mesh setup appears in the overview of what a mesh network is.

What Are the Operating Modes of a Wireless Access Point?

A wireless access point runs in one of several modes, with access point mode as the default that bridges wireless clients onto the wired LAN. The selected mode sets how the access point connects to the rest of the network.

The list below names the common operating modes of a wireless access point and the job each mode performs.

• Access point mode. Access point mode bridges wireless clients onto a wired network through an Ethernet cable, which is the standard role of a dedicated access point.
• Repeater mode. Repeater mode rebroadcasts an existing wireless signal to extend coverage without a cable, at the cost of shared radio bandwidth.
• Bridge mode. Bridge mode links two wired network segments over a wireless connection, joining two buildings or floors without a cable run between them.
• Client mode. Client mode connects a wired-only device to a wireless network, so the access point acts as a wireless adapter for that device.

Access point mode keeps full wired backhaul speed, while repeater mode trades speed for reach. The choice between a cabled access point and a wirelessly linked node mirrors the difference between wired access points and the wireless backhaul used in a mesh network.

Key Takeaways

• An access point adds Wi-Fi. A wireless access point bridges wireless clients onto an existing wired network over IEEE 802.11.
• An access point bridges, not routes. An access point works at layer 2 and assigns no IP addresses, unlike a router at layer 3.
• A home router includes one. A home router contains a built-in access point alongside its router and switch sections.
• Multiple access points share one SSID. Several access points use one network name and separate channels so devices roam between them.
• Access points differ from mesh. Access points use a wired backhaul, while mesh nodes link to each other wirelessly.

Last Thoughts on the Wireless Access Point

A wireless access point adds Wi-Fi to a wired network by bridging wireless clients onto the LAN over the IEEE 802.11 standards. An access point connects to a switch or router by Ethernet, broadcasts an SSID, and passes the IP addressing job to the router, so an access point extends a network rather than creating one.

The device that hosts a built-in access point is detailed in the overview of what a router is, and the wireless alternative that links nodes without cabling is covered in what a mesh network is. Improving coverage across a building is covered in the guide to improve a Wi-Fi signal, and the wider wireless standard behind every access point appears in what Wi-Fi is.