Unstructured Supplementary Service Data (USSD) refers a protocol used by GSM cellular devices, such as M2M products or a cell phone, for a bilateral communication between the computers of the mobile network providers and the equipment. The protocol is typically used in balancing checking, adding credit, and in adjusting account settings. Any instant a user dials *(number)# and press send, USSD is being put to use. The protocol is used by cellular phones in communicating with the service provider. Applications built using the USSD may have a single short cord such as that in the form *142*2# or *123#, which is assigned by the telecommunication company providing a network for the mobile phone.
How USSD Works
A mobile application built with using USSD has a unique shortcode. The shortcode, such as *123#, gets sent to a subject server using a phone. After posting the system, a menu or question is received. The user then responds to the menu options. After responding, the user can get a fail or success message, which shows the end of the process. Mobile users use the cell phone for a variety of reasons, including crediting airtime, checking balance, and transferring money. The use of USSD services does not lead to additional costs for the mobile users, and this has made it easy for network companies to build facilities around them as a way or to reach the people in different manners.
Another approach that can aid to understand better how the USSD protocol functions include considering the use of a location tracking device with cellular connectivity. The tracking device first has to be fitted with a SIM card or eSim. After requesting the location of the device through the front end, such as a smartphone APP, a command gets sent through the tracking backend of the mobile network as a way of communicating a USSD message to the tracking device, as a form of alphanumeric characters. In fact, the characters do not necessarily need to comprise of only numbers, but can also contain letters, depending on the desired objective (e.g., *abc12345#). The device the gets an instant USSD message back to the mobile network. The cellular network is forwarding the message to the tracking backend and pushing location coordinates to be visible on the front end, in the case of tracking.
Other Beneficial Functions Fulfilled by USSD
Among the benefits of USSD includes its low cost, global coverage, having no roaming costs, as well as ensuring power efficiency. Mobile money transactions developed through the use of USSD have also managed to capture the unbanked sector of the population. The promotion of these mobile financial services has gone a long way to increase economic inclusion for this sector of the society, a good example of reality behind USSD protocol benefits.