
📶 Telecom · State Machine
The states a mobile SIM goes through, from stock in the warehouse to active service, suspension, porting out and deactivation.
Drawing diagram…
State machine for a telecom SIM: In Stock, Allocated to a retailer, Sold, KYC Pending, KYC Verified, Active. An active SIM can be Suspended for non-payment or a lost-SIM report and reactivated, Ported Out to another operator, or Deactivated after 90 days of suspension.
stateDiagram-v2 [*] --> InStock InStock --> Allocated: Sent to retailer Allocated --> Sold: Customer buys Sold --> KycPending KycPending --> KycVerified: e-KYC passed KycPending --> Rejected: KYC failed KycVerified --> Active: Number provisioned Active --> Suspended: Unpaid bill or lost SIM Suspended --> Active: Paid or SIM replaced Suspended --> Deactivated: 90 days suspended Active --> PortedOut: Moves to another operator Active --> Deactivated: Customer closes Deactivated --> [*] PortedOut --> [*] Rejected --> [*]
A simplified 5G standalone network: phones and radio sites, the 5G core network functions, and the connection out to the internet.
The IT stack of a mobile operator: business support systems (CRM, billing, orders) and operations support systems (inventory, provisioning, assurance).
How a subscriber moves their number to another operator: porting code, request through the clearing house, donor approval and cutover.
What happens when a customer recharges a prepaid mobile: plan selection, payment, balance update in the charging system and confirmation.
How network usage becomes a customer bill: call detail records, mediation, rating against the plan, billing and invoicing.
A schema for subscriber data: customers, accounts, subscriptions (numbers), plans, SIMs and bills.