Wireless Technologies & Limitations
"WiFi" is a trademark of the WiFi Alliance and the brand name for products using the IEEE 802.11 family of standards. It is also known as wireless LAN (WLAN) and can refer to as any of the established 802.11 standards: 802.11a, 802.11b, 802.11g, 802.11n and 802.11ac. New wireless standards will continue to evolve.
The wireless technology is fast evolving, and consumer needs to be aware of their PC & router capability and limitation, so as to avoid misunderstanding and mismatch in performance expectation and surfing experience.
A device enabled with WiFi, such as a personal computer, video game console, smart phone, or Smart TV, can connect to the Internet via a wireless router that connects to a cable modem or optical network terminal.
Today, most of the WiFi capable equipment and devices in the market are dual-band operating at 2.4GHz (802.11n) and 5GHz (802.11ac).
WiFi 802.11ac product manufacturers would typically market their product with AC#### classifications. Here is a table decoding some of the commonly seen numbers.
MIMO (Multiple Input, Multiple Output)
MIMO is a wireless technology that uses multiple antennas that are used as source (transmitter) and destination (receiver) to transfer more data at the same time. Devices with a single antenna and radio are 1x1 MIMO device and are able to communicate via a single stream of transmit or receive. 2x2 MIMO devices with dual antennas and radios communicate via 2 streams of transmit and receive. 3x3 MIMO devices with 3 antennas and radios are capable of transmitting and receiving via 3 streams.
SU-MIMO vs MU-MIMO
Single-user MIMO (SU-MIMO) debuted with the 802.11n WiFi standard in 2007. Multi-user MIMO (MU-MIMO) was introduced with the 802.11ac as the next generation technology which is commonly known as 802.11ac Wave 2 in the industry.
Wireless Range Extenders / Repeaters / Signal Boosters
A common home option, a wireless extender picks up your router’s WiFi signal and repeats it. You plug it into a socket and “pair” it with your router. It then pushes your original signal further, so you can connect to it. Extenders boost range, but usually halve your signal’s strength.
An increasingly popular WiFi solution is a mesh network. They operate by connecting multiple “nodes” in a space. Unlike an extender which repeats one router’s original signal, each node acts as an individual router, with its own dedicated WiFi signal. By spreading nodes across your home, it “enlarges” your WiFi network, giving you more WiFi points to access. An example is Google Wifi, which you can get with StarHub Broadband. It’s easy to set up, flexible and can service a range of home sizes up to 251 square metres. Check out Google Wifi with StarHub Broadband.
Factors Affecting Wireless Network Connection (Speed Performance or Coverage)
As wireless signals travel through the atmosphere, they are sensitive to different types of impediments and interference as compared to wired network.
Physical obstruction: The number of walls the WiFi signal can pass through is determines by density of the materials used in a building’s construction. Concrete and steel walls are difficult for a signal to pass through. These structures will weaken or at times completely prevent wireless signals.
Interference: WiFi network operates at 2.4GHz and 5GHz band, other wireless devices using the same frequencies could cause interferences, resulting poorer WiFi receptions. Microwaves, cordless phones, baby monitors, wireless game controllers and Bluetooth devices all operate on the same wave spectrum of 2.4GHz as WiFi routers. Avoid cluttering source of interference around the router.
Shared bandwidth: The bandwidth of wireless network is shared among all the wireless users, so the more users you have, the slower the network becomes. Downloading torrents, for example, might cause other users to experience a slowdown in network speed. It is a good practice to protect your WiFi network with a strong WiFi password, to prevent unauthorized user from “stealing” the bandwidth.
Distance: If you're sitting near a wireless router or access point, you will experience a faster network speed. But if another person is sitting far from the wireless router or access point, the network speed of both computers will drop drastically.
Speed of connected device: The achievable download and upload speed of the device connected to the WiFi network is also dependent on the device itself. A mobile phone with better processor and more advanced antennas and radios design will promise higher download and upload speed.
Location: Where an Access Point or wireless router is placed also makes the difference. Place the devices in higher ground to reduce the impact of physical objects.