Overview
USSD (Unstructured Supplementary Service Data) enables grievance submission from any mobile phone - no smartphone, internet connection, or data plan required. Workers dial a short code (e.g., *123#) and navigate a menu-driven interface to submit their concerns.
Why USSD?
Universal Access: Works on any GSM phone, including basic feature phones.
Zero Data: Uses signaling channel, not mobile data - completely free for users.
Offline Areas: Works anywhere with cellular signal, no internet needed.
Familiar: Same technology used for airtime balance checks, mobile money.
Sample User Flow
Screen 2: Location
Where did this happen? 1. Palma Camp 2. Processing Plant A 3. Processing Plant B 4. Admin Building 5. Transport Hub 6. Other (type name) Reply:
Screen 3: Description
Briefly describe your concern (max 160 characters): Example: "Not paid overtime for November, supervisor says wait until January" Reply:
Screen 4: Contact (Optional)
Want us to follow up? 1. Yes, call me at this number 2. Yes, different number 3. No, stay anonymous Reply:
Screen 5: Confirmation
Thank you. Your concern has been recorded. Reference: GV-2024-0847 Category: Wages/Payment Location: Processing Plant B We will review within 48 hours. END
Key Advantages for Mozambique Context
Any Phone
Works with Nokia 3310, basic phones - no smartphone needed
Low Signal OK
USSD works with minimal signal strength where data fails
Free for Workers
USSD sessions don't consume airtime or data
Local Languages
Menus can be in Portuguese, English, or Swahili
Instant
Real-time session, no waiting for app to load
Private
No app history, no screenshots - session disappears
Technical Implementation
USSD integration requires partnership with a local mobile network operator (MNO) or aggregator:
| Provider | Coverage | Setup | Per Session |
|---|---|---|---|
| Africa's Talking | Mozambique (via Vodacom, Movitel) | ~$100-500 | $0.01-0.02 |
| Infobip | Multi-country coverage | Variable | $0.02-0.05 |
| Direct MNO | Single network | Higher | Negotiable |
How it works: When a user dials the USSD code, the MNO sends a request to our server. We respond with menu text, receive the user's selection, and continue the conversation. Each screen has a ~180 character limit. Sessions timeout after ~120 seconds of inactivity.
Limitations vs. Voice/WhatsApp
| Aspect | USSD | Voice/WhatsApp |
|---|---|---|
| Detail Capture | Limited (160 chars per field) | Full narrative possible |
| Emotion/Tone | Not captured | Voice tone, Hume emotion detection |
| Clarification | Pre-set menu only | Agent can ask follow-ups |
| Evidence | Text only | Voice recording preserved |
| Best For | Simple, urgent reports | Complex, sensitive cases |
Recommended Use Case
USSD is ideal as an initial intake channel - capturing the category, location, and brief description. For complex cases, the system can offer to call the worker back via the voice agent for a fuller conversation. This hybrid approach maximizes accessibility while ensuring quality data capture for serious grievances.
Implementation Timeline
| Phase | Scope | Duration |
|---|---|---|
| Phase 1 | Africa's Talking account setup, USSD code application | 3-7 days (approval dependent) |
| Phase 2 | Menu flow design, webhook endpoint development | 2-3 days |
| Phase 3 | Database integration, multi-language support | 2-3 days |
| Phase 4 | Testing across networks, edge case handling | 2-3 days |
Note: USSD code approval from MNOs can take 1-4 weeks depending on the country and operator. Development can proceed in parallel using sandbox/test codes.