How does the phone measure the strength of Wifi?

For those in the 80s and 90s, the Internet was known in the early days . To use the Internet at the time, you needed an extension cord and a dial box connected to a phone line. Whenever there is a phone, the Internet will lose the connection. Later, the dial-up network evolved into an Ethernet connection, but this new type of connection still needed a wire that ran throughout the house.

Wifi makes connecting to the network a lot simpler. Wifi connection makes the cables become obsolete, you only need an access point for many independent devices connected to the Internet at the same time. Word of mouth of today's generation when someone's home is no longer asking for a glass of water anymore, but asking for a Wifi password.

Wifi has become so popular that users prefer using it over mobile data services of network providers. Surely, you also had a painful time after sitting for hours surfing on the phone to discover that you are using mobile data instead of Wifi.

However, Wifi has a limit on its use, only devices in its coverage area can access the Internet. The strength of the Wifi signal is displayed on your device, but how can your device measure the strength of the Wifi signal? First, let's find out what Wifi is.

What is Wifi?

Wifi was developed in the 1990s by Dr. John O'Sullivan and his associates under the Wifi Alliance Alliance. Wifi is used for wireless local area network (WLAN). It allows multiple devices to be able to connect to the Internet at the same time such as phones, tablets, laptops, TVs, printers, etc. In addition, it also allows these devices to share data with each other, create off a local area network connecting devices. Wifi uses the Internet connection protocol (IP) to communicate, so they are much better able to communicate than ground radio. Basically, the language of the Internet creates Wifi waves with complex structures.

Wifi is a safe radio technology, based on the use of radio waves to connect between devices. There are many different types of electromagnetic waves with frequencies between 30 Hz and 300 GHz, each of which is generated by a generator. A transmitter is an electronic device that is connected to a broadcast antenna.

Wifi currently transmits about 60% of global Internet traffic.(Photo Credit: Rido / Shutterstock).

Wifi signal is transmitted at frequencies of 2.4 GHz and 5 GHz. The lower the frequency, the farther the signal goes, so the Wifi with 2.4 GHz frequency has wider coverage. However, in return it will have a lower speed than the frequency of 5 GHz. Wifi at 5 GHz gives higher access speed, but can only be used in a small range. Wifi can be used on both frequencies to help them reduce interference and overcome obstacles to ensure a strong connection to your device.

How does a router work?

The router is the bridge between the access device and the Internet via Wifi. True to its name, this device routes traffic between the Internet and access devices.

The router allows multiple devices to access the Internet at the same time.(Photo Credit: Macrovector / Shutterstock).

Inside the router are low-power radio transmitters and receivers to convert radio signals into electrical signals and vice versa. A router has a maximum coverage of about 90m, this number depends on the manufacturer, the characteristics of each product, the type of wall and the obstruction between devices.

The router sends and receives data from the devices connected to it. The router has a very orderly workflow. Each device connected to the router is given an IP address, so that it also forms a local area network. It works similar to a courier service, whose main cargo is data. Data will be transferred to the recipient via the assigned IP address, thus avoiding the possibility of data confusion during the exchange.

How strong is the Wifi signal?

There is no set standard for manufacturers to measure Wifi strength, although the Signal Strength Index (RSSI) is a commonly used measurement system. Some routers use the 0-60 scale (RSSI), others use the 0-255 scale (RSSI).

To make these parameters easy to understand, Wifi strength is measured in dBm (decibel-miliwatts) . This unit represents strength through power difference in decibels (dB) compared to milliwattes (mW). The dBm value is negative, the strong Wifi signal is about -30 dBm and the unusable Wifi signal will be about -90 dBm.

How do devices measure the strength of Wifi waves?

Similar to routers, Wi-Fi capable devices are equipped with an internal radio transmitter and receiver that converts radio signals into electrical signals and vice versa. This is a mandatory requirement for the device to be able to connect to the router to send and receive data (or with any other type of Wi-Fi hotspot such as a mobile hotspot). Therefore, the strength of the signal is determined between the receiver and the transmitter between the device and the router.

As mentioned above, the Wifi signal will weaken with increasing distance and when there are many obstructions between the access device and the router. Weakness is shown by the decrease in the dBm index (the unit that the Wifi strength). The location of the device in the coverage area will indicate the dBm strength indicator of the Wifi signal.

Decreasing dBm means weaker WiFi signal.(Photo Credit: Rido / Shutterstock).

When the Wifi connection on the phone is activated, the transmitter will also be turned on and connected to the router. At that time, the phone will determine its location in the area of ​​how many dBm and evaluate the strength of that Wifi signal. The strength of the Wifi signal is represented on the phone as a bar. If the device is within the range of -30 to -50 dBm, the signal column will show all the lines.

If it is within the range of -80 dBm, the signal column will only be one line, which means that the Wifi you are connecting is very weak. If it is within -90 dBm or more, the device will not be able to connect and notice there is no WiFi around you.

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