Eyeline USSD Call-Back

Overview

When a phone call cannot be placed, a subscriber can send a free SMS to the other party asking to call back. The SMS is initiated by a USSD request of the following kind: *110*XXXYYYHHZZ#, where XXXYYYHHZZ is the other party’s phone number and the whole string is a USSD Phase 1 request (the prefix 110 can be chosen to be different). The Service can also be initiated from a USSD Phase 2 self-care operator’s portal, given there is one.

The mobile operator would usually put a limit on the number of free requests per day. The most common limit is five free requests per day so this limit is used in this particular software version.

The other party, to which the caller could not place the call, receives an SMS as if from the caller:“Please Call Back. Sent at HH:MM DD/MM/YY” (where HH = hour, MM = minutes, DD = day, MM = month, YY = year). The caller also receives an SMS notification about successful request.

Operator Benefits

Service gives the operator the following benefits:

• Additional profit due to a larger voice traffic. For prepaid subscribers, running out of money is a real problem when important calls are to be made. For example, when subscribers limit their children’s or business phone use. The system makes it possible to communicate even with non-positive balance. Such calls, according to our statistics, are initiated on daily basis from 10% of subscriber base. If 20-50% of those SMS are answered by a call that would have never happened otherwise, voice traffic can potentially increase by more than 1.5%.
• Easy expansion. “Call-Back” can easily accommodate subscriber growth by increasing the Service’s productivity.
• Easy integration. The system uses open standards, it can be integrated with any network infrastructure of mobile operator, and it does not require additional expensive network installations given the operator has basic infrastructure components such SMS and USSD centers.
• Easy Promotion. The Service can be promoted through the operator’s portal where the Service can be initiated.
• Additional profit from advertising. “Call-Back” can be integrated with Eyeline Sharp Ads. Such integration makes Eyeline Call Back notification a mass information and advertisement channel.

Subscriber Benefits

“Call-Back” improves quality of service for subscribers. The Service offers the following attractive features:

• Ability to stay in touch in any situation. With “Call Back” subscribers will never be left without means of communication when there is no money on mobile account.
• Inform busy people about your need to talk – for FREE! “Call-Back” can be used to inform your busy partner about a need to talk without spending any money.
• Free in roaming. This service keeps you in touch in roaming and it is free of charge for the caller.
• Easy to use. “Call-Back” is easy to use because subscribers return calls by pushing just one button. Subscribers send notifications by dialing one code string.
• Does not require any configuring. Default settings enable subscribers to use the Service without any additional configuration.

System Architecture

The Service is an SME application connected to SMS and USSD center(s). The Service receives subscriber’s request from the USSD center in the form of a direct call to *110*9XXYYYHHZZ# or as a selection in the operator’s USSD portal.

“Call-Back” requires the following components:

• A hardware platform for installation of application software for processing of incoming USSD requests and preparation of corresponding SMS notifications.
• USSD center with SME connection via SMPP 3.4 protocol.
• SMS center with SME connection via SMPP 3.4 protocol.

Integration with SMS and USSD centers is based on SMPP v3.4 protocol (see Fig. 1).

Fig. 1. “Call Back” Connections in a GSM Network