Wireless networking is ubiquitous in homes and businesses alike. The
rise of devices that rely on these wireless networks – smart phones,
tablets, smart TVs, gaming consoles, digital set top boxes and even
thermostats – make wireless coverage throughout your home increasingly
important. The quickest and easiest way to achieve this is through the
use of a wireless range extender.
 |
| Wireless
networks are often limited by the placement of the wireless router.
Coverage in the far corners of the home, often bedrooms, can be weak or
completely nonexistent. |
Networks and the devices that connect to them have evolved greatly over
the last decade. It used to be that stationary desktops were connected
together through wires, while access points supported a handful of
mobile devices. Now, HD video is being streamed to multiple wireless
clients simultaneously in the far corners of the average home. These
wireless network connections must deliver offer optimal performance in
order to support the amount of bandwidth consumed by streaming content,
as well as the range and reliability needed to reach tablets and set-top
boxes.
Frequencies
By definition, the 802.11ac standard improves
range and bandwidth by offering dual-band support, beamforming and
improved performance over its predecessors. (You can get more
information on the technical aspects of 802.11ac in
our story on 802.11ac-capable routers.)
Just remember that optimal performance on ac's 5GHz band requires a
strong signal, which limits range compared to 2.4GHz. A potential
solution to this conundrum is to implement an 802.11ac-capable wireless
range extender, which will expand the reach of your network to the dark
corners of your home.
802.11ac range extenders support 2.4 and 5GHz, both for connecting to
existing wireless networks and ensuring client connectivity. In most
cases, range extenders pass network traffic using the wireless client's
band – 2.4GHz devices naturally go through the 2.4GHz connection and
5GHz clients through a 5GHz link to the router (though in some cases you
can configure the range extender to use one band or clients and the
other for connectivity back to the router). 802.11ac range extenders,
like wireless routers and other Wi-Fi hardware, are marketed based on
their advertised data rates. AC750 devices support 300Mb/s through
2.4GHz and 433Mb/s using the 5GHz signal, while AC1200 offers 300Mb/s
for 2.4GHz and 867 Mb/s on 5GHz, though actual data rates are a fraction
of those advertised rates.
802.11ac Speed Ratings
| Type | 2.4GHz Mb/s | 5GHz Mb/s |
| AC600 | 150 | 433 |
| AC750 | 300 | 450 |
| AC1000 | 300 | 650 |
| AC1200 | 300 | 867 |
| AC1300 | 450 | 867 |
| AC1450 | 450 | 975 |
| AC1600 | 300 | 1300 |
| AC1750 | 450 | 1300 |
| AC1900 | 600 | 1300 |
Functionality And Placement
Range extenders are often physically similar
to other wireless networking products you would typically find in a home
or office, but they differ significantly in configuration and
functionality. Wireless routers – perhaps the most common wireless
networking product found in homes – connect directly to the broadband
modem, sharing the Internet connection to wired and wireless devices, as
well as providing basic network services like DHCP, NAT and a basic
firewall. Access points also connect to existing wired networks, but
simply provide access to an existing local network and its associated
services. Wireless access points are often used in conjunction with an
existing router – either wired or wireless – and wireless clients
connect to the internet through this device.
Another type of wireless networking device is a media bridge, which
allows a device without wireless connectivity to connect to a wireless
network without having to run Ethernet cable. Media bridges connect to
the wireless network as clients, and share the network connectivity
through an RJ45 port. Range extenders share characteristics of both
media bridges and wireless access points – connecting to an existing
wireless network and then extending the wireless network as an access
point and typically offering Ethernet connectivity as well. In most
cases a router is needed on the network to provide DHCP and NAT, which
allow network devices to reach the Internet.
 |
| A
wireless range extender should be placed centrally, between the
wireless router and potential wireless clients, in order to optimize the
wireless signal throughout your home. |
The physical placement of your wireless range extender will depend
largely on the nature of your environment and the devices leveraging the
expanded wireless footprint. A central location between the wireless
router and wireless clients is ideal, however the location of wired
computers could influence placement of the range extender as well. Other
areas of potential interference like large metal objects should be
avoided, as should large electronic devices. If your intent is to
utilize 5GHz frequencies for optimal performance, you should remember
that your range is more limited than 2.4GHz networks.
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Software And Firmware
Many modern hardware devices have embedded
software, commonly known as firmware, which allows the manufacturer to
patch bugs or add features. Some common examples of firmware you may be
familiar with are cellular phone ROMs and your motherboard's BIOS. In
most cases, firmware is read-only to the device, and specific steps must
be followed in order to perform an upgrade. The read-only nature of
firmware provides a layer of security by helping ensure malicious code
doesn’t get applied to the device. Firmware updates should be handled
with care, as misapplied firmware updates are a common reason for device
failure (known as bricking).
In general, the biggest difference between a wireless range extender
and a wireless router or access point is its firmware, as this
determines the capabilities that are enabled on the device and
ultimately drives the hardware. Unfortunately, firmware is rarely
interchangeable between devices, so don’t plan on applying a router
firmware to your range extender anytime soon.
For the adventurous types there is an open-source firmware
alternative for Wi-Fi routers, which is beginning to offer support for
range extender hardware. DD-WRT is a Linux distribution designed for use
on wireless networking hardware. A list of supported devices is
maintained on the project website, so check there in order to determine
if your hardware is supported. If you’d prefer to re-purpose an old
router to perform range extender duties, DD-WRT offers comparable
functionality. Be aware that flashing a custom firmware to your device
could potentially void your warranty.
Hardware
Range extenders commonly come in two form
factors: devices designed to sit on a shelf or mount on a wall like a
wireless access point or router, and those that mount directly on a
power outlet. Both form factors offer some basic functionality that you
can expect to find on any range extender. Antennas for the wireless
network can be either internal or external, though external antennas can
be expected to provide better signal. LED indicators are usually made
available in order to be able to see the status of your network
connectivity or provide other troubleshooting information.

Most range extenders designed to sit on a shelf offer connectivity for
wired devices in the form of four or five gigabit Ethernet ports.
Additionally, many of these devices provide a USB port to accommodate
storage for file sharing or media server purposes, or even the option to
share a USB printer on your network. Because of their size, these range
extenders often provide increased performance over their outlet-mounted
cousins through more robust processors or higher-powered amplifiers.
Outlet-mounted range extenders are often smaller in order to reduce
weight and not place stress on the outlet. Because of size restrictions,
these range extenders usually offer only one Ethernet port for wired
devices and no USB port, and may not have the same performance
capabilities as larger shelf-mounted units. What they give up in
performance and capability they make up for in convenience. They're
perfect for placing in a closet, hallway or behind furniture.
External And Internal Components
Most range extenders feature similar
components – and often a similar form factor – as what you’d expect from
a wireless router or access point. Many of the hardware features that
make up a range extender are comparable across devices and vendors, but
there are also features that only make an appearance occasionally.
In general, it’s safe to assume that a range extender will include
core components like a processor and memory (both RAM and ROM) to store
and run the device’s firmware, and to handle network traffic and other
device functions. As with any piece of electronics, better performance
from those components is always desirable, so some attention should be
paid to their specifications.
Another component always found in a wireless range extender is the
radio that handle wireless communication. Dual-band range extenders that
offer support for both 2.4 and 5 GHz frequencies will typically have a
wireless chipset and one or more amplifiers for each frequency, as well
as the antennas used to optimize the signal. The size and placement of
the antennas often has an impact on signal strength, and can be a major
selling point.
 |
| Interior
shot of a Linksys RE6500 showing 1) antenna jacks, 2) heat sink for
processor, 3) Ethernet switch ports, 4) power input and WPS button, 5)
3.5 mm audio port, 6) transformers, 7) memory, and 8) radio chipset.
The router’s reset button and flash a |
Externally, range extenders often provide at least one Ethernet port,
but some models offer four to six ports for wired connectivity. USB
ports are also common, though their usage can vary wildly between
devices, facilitating media server functionality, file sharing or print
serving. Other options available on some range extenders include audio
outputs for streaming music or other I/O like eSATA.
Some range extenders have on/off buttons, though others automatically
power on when you plug them in. A button to enable the WPS feature
(Wi-Fi Protected Setup) is common, as is a button (typically recessed)
to reset the device to factory defaults.
Configuration
Most range extenders offer one of two
configuration methods. The first and by far the simplest uses WPS (Wi-Fi
Protected Setup), which involves pressing physical buttons on the
wireless access point and range extender in order to securely pair the
two devices. WPS provides easy setup but offers limited configuration
options without further tweaking. Power users are better served walking
through the manual configuration method, which typically involves a
fairly straightforward setup process:
- Connect your computer to the range extender using a wired or wireless interface.
- Access the configuration website by name or IP address.
- Configure the range extender to connect to your existing wireless network – preferably using both 2.4 and 5GHz connections.
- Set up a new SSID for both frequencies.
- Connect your wireless clients to the new range extender SSIDs.
The most difficult step in configuring your range extender is usually
connecting to the configuration page, particularly after the device has
been connected to your network and it pulls an IP address using DHCP.
Most range extenders offer a method of connecting to your range extender
without having to guess at the IP address. One of the most common
methods used to provide access to your range extender configuration is
using a DNS domain name (such as
myrangeextender.com)
that resolves only if your computer is connected to the range extender.
Other devices use the Universal Plug and Play (UPnP) standard, which
allows your computer to recognize the range extender as a configurable
wireless networking device. In some cases, you may have to look through
your router’s DHCP client table, but you should consult your range
extender’s documentation in order to determine the preferred method of
accessing the configuration page.
 |
| Screenshot
of the configuration page for a Netgear EX6200 WiFi Range Extender.
Note that both the 2.4 GHz and the 5 GHz networks are being extended. |
It’s worth noting that a wireless range extender functions differently than an access point configured using
Wireless Distribution System (WDS).
WDS functions at a lower level – using the devices radios but not Wi-Fi
– and is typically vendor-specific. Wireless range extenders use
existing Wi-Fi networks, allowing them to support connection to any
wireless access point that supports the proper bands.
The Future
It’s interesting to consider how extenders
will fare in the future. Designed to make up for the range-related
shortcomings of Wi-Fi, it doesn’t seem that extenders will be going
anywhere in the short term thanks to WiGig. Considered an in-room
technology, WiGig, also known 802.11ad, may have transfer speeds of up
to 7 Gb/s, but throughput suffers dramatically as soon as you step out
of a room. Because of this range limitation, 802.11ac will have a
continuing role as a backbone for the home network, extending the need
for Wi-Fi extenders, at least for a little while longer until 802.11ax
comes along.
If anything, two current enterprise standards that are now in
development for the consumer market, 802.11k and 802.11r, are being
geared up to improve roaming between access points, routers and
extenders. With current extenders, a second set of SSIDs is created so
that the extender can service devices out of range of the main router,
which works great for stationary wireless devices. However, roaming
devices would need reassigned SSIDs to stay connected. Used together,
802.11k and r provide a service called Seamless Roaming; 802.11k lets
the client device quickly identify and remember an available access
point when a signal weakens, while 802.11k uses a feature called Fast
Basic Service Set Transition (F-BSST) to streamline the authentication
process between access points. Once established as a consumer feature,
Seamless Roaming can eliminate the need of having more than one or two
SSIDs.
 |
| Diagram showing how 802.11k and 802.11r can help wireless clients roam seamlessly. |
Another wireless networking technology that may have an impact on where
extenders are used is mesh networking. Made up of small, individual
networking nodes, mesh networks for the home are designed to produce
reliable coverage. Each node in the network acts like a relay providing
coverage for its particular zone and can back up a neighboring mesh node
in case the latter stops working. The concept of mesh networking is not
too new as it’s used in both enterprise and metropolitan environments.
However, home usage is still in its infancy. If priced correctly and the
performance is competitive enough, we can see mesh networking, in one
form or another, affecting the Wi-Fi extender market.
Source :
tomshardware
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