Page 192 - ITU-T Focus Group Digital Financial Services – Technology, innovation and competition

ITU-T Focus Group Digital Financial Services
Technology, Innovation and Competition

C ACCESS TO BEARER TECHNOLOGY

5 USSD access

5.1 Overview

USSD is a standard within the GSM and 3G specifications. As with SMS, USSD is an artifact of the original 1980s
GSM specification, used by MNO engineers to send and receive test messages over the signaling channel of
GSM networks without interrupting customer calls.

It is both a GSM bearer technology and a DFS User Interface (UI). It does not require any additional installations
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by customers, nor does it require a IP-based data access connection by customers. It can be used for
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transmitting information and accessing standard services and Value Added Services (VAS). As a result, USSD
has been termed ‘The Third Universal App.’ USSD is session-based and activated either by users inputting a
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series of predefined star (*) or hash (#) commands on the mobile handset, or via a session initiated by the
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MNO or a SP.
In both methods, the user is presented with a numbered menu and can use the mobile keypad to respond to,
and to input in any data required. While the USSD specification allows a USSD session of up to 600 seconds,
typical allowance by MNOs for third party services is up to 180 seconds, with 120 seconds being the typical
maximum time allowed for the entire USSD session by MNOs.
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Access to USSD is usually via a MNO’s USSD gateway. MNOs may give access to their USSD facilities to third
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parties who can craft their own USSD menus and session timeouts, usually for VAS and DFS access. In many
countries, a USSD gateway is also offered by third party aggregators, who may in turn resell turnkey USSD
access to entities – such as banks and micro finance institutions (MFIs) - who may not have the technical ability
to properly integrate into the MNO’s USSD gateway.

Large deployments that rely primarily on USSD include bKash in Bangladesh, WING in Cambodia, EasyPaisa in
Pakistan, MTN Money and Airtel Mobile Money in Uganda, ZAAD in Somaliland, M-PESA and Tigo in Tanzania,
and EcoCash in Zimbabwe. 84

The regulatory, commercial, and technical steps needed by a third party DFS SP to obtain access to a USSD
gateway could include: 85

• Obtain consent to integrate into the USSD or STK gateway of the MNO or aggregator.

78 GSM (Global System for Mobile Communications, originally Groupe Spécial Mobile), is a standard developed by the European
Telecommunications Standards Institute to describe the protocols for second-generation (2G) digital cellular networks used by
mobile phones, first deployed in Finland in July 1991. It has become the de facto global standard for mobile communications with
over 90 per cent market share, operating in over 219 countries and territories. See www. gsma. org .
79 As USSD is session-based, it can only be accessed or be consistently accessible when there is robust communication with MNO
base stations. Poor mobile signals and substandard antennas in some mobile phones may cause USSD session initiation and
sustainability issues.
80 Perrier, T et al (2015) USSD: The Third Universal App, available at http:// bderenzi. com/ Papers/ perrier- dev2015. pdf
81 These relate to combinations of the use of the * [star] and # [hash] keys respectively on the mobile handset. The hash key is also
known as the ‘pound key’.
82 Response times for the customer to answer challenge questions – such as a need to select 1, 2, 3, or 4 on a USSD-based DFS
menu, or type in a recipient’s phone number or name in a P2P transaction - may also have their own timeout sequences, either
set by the SP, or aggregator or forced by the MNO.
83 A gateway is the collection of hardware and software required to interconnect two or more disparate networks, including per-
forming protocol conversion. See Exhibit 3 on how USSD gateways fit into overall MNO architecture.
84 Hanouch, M & Chen, G (2015) Promoting Competition in Mobile Payments: The Role of USSD, available at https:// goo. gl/ po24bd.
85 The sequence and requirements for getting access to USSD short codes and a USSD gateway as described here are stylized, and
will invariably differ in various jurisdictions.

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