USSD: A Communication Technology to Potentially Ouster SMS Dependency
This tutorial provides an overview of Unstructured Supplementary Service Data (USSD) technology as compared to Short Message Service (SMS). It presents information and guidance but does not support a specific plan of action, which would require additional information and insights into each situation. The vulnerabilities, analyses, and risks shown and analyzed in this paper are intended to be indicative of the risks an application vendor, third-party host, or network operator might face. The analysis given should not to be considered an exhaustive or fully objective list.
It is important that risks be assessed and validated based on the situation, the intended functionality to be offered, and the process controls that will be required or are already in place. Additional guidance should be sought wherever necessary before taking any action.
Value Added Services (VAS) have become an indispensable part of the products and services offered by mobile/telecom operators today. With growing competition in the telecom industry, operators must be diligent in how they price both new and existing services. They are therefore looking for faster and more economical technologies.
USSD technology is the key solution in all cases. It is a messaging service that is almost seven times faster than SMS and is highly cost effective. The operations involved in using USSD are simple and handset independent, which means the service can be accessed from almost any mobile device (from old cell phones to the latest smartphones).
From the core network to the internet, the reach of modern USSD services is rapidly transforming the telecom cloud into a services cloud. USSD is fast emerging as the communication protocol, which can ouster the dependency on SMS for quick messaging services.
Scope and Assumptions
This tutorial discusses the key features of USSD technology and its economic viability in providing VAS and other services. However, it does not cover:
- Implementation details of any specific application
- Generalized rules based on which USSD codes are derived (USSD codes are derived using a set of rules and are affixed to identify a specific service. Users must enter the defined code to access the service, but do not need to bother about its derivation.)
- Detailed description of the Multi Media Interface (MMI) commands used in USSD
This technical tutorial assumes the reader has a fair knowledge of the GSM network.
Have you ever typed a code starting with an asterisk (*), number set, and hash (#) on your mobile? If yes, then, knowingly or unknowingly, you have already been using USSD service.
USSD is a communication protocol used to send text messages between a mobile phone and applications running on the network. It is a messaging service used in Global System for Mobile Communications (GSM) networks similar to SMS, where it sends data utilizing the signaling channel. However, unlike SMS which follows a store-and-forward oriented message transaction; USSD provides session-based connections. Because of its real-time and instant messaging service capability, USSD service is up to seven times faster and much cheaper than SMS for two-way transactions. It is a technology unique to GSM networks and is the standard for transmitting information over GSM Signaling Channels.
USSD is as similar to speaking to someone on a phone as SMS is to sending a letter.