---
title: "Wireless Technologies and SIM Management"
slug: "wireless-technologies-and-sim-management"
updated: 2026-07-23T09:44:13Z
published: 2026-08-10T20:23:40Z
canonical: "help.idibilling.com/wireless-technologies-and-sim-management"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://help.idibilling.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Wireless Technologies and SIM Management

A quick overview of wireless technologies is provided below.

SIM Management is covered in this [SIM Management topic](/v1/docs/sim-management).

#### CDMA/TDMA/AMPS

These technologies are what most cellular phones use today in the United States.

- CDMA - Code Division Multiple Access (each call gets a unique code that is spread over the available frequencies)
- TDMA - Time Division Multiple Access (each call gets a certain portion of time on a designated frequency)
- AMPS - Advanced Mobile Phone Service (analog cellular)

#### GSM

GSM, or Global System for Mobile communications, is a fast-growing digital wireless technology used by the majority of the world. It differs from TDMA/CDMA/AMPS in that GSM phones:

- Use a SIM card, a removable smart chip.
- Use narrow band TDMA.
- Operate at either 900 MHz or 1800 MHz in Europe and Asia, and 850 or 1900 MHz in the US

#### SIMs

SIMs are the brains of a GSM phone, and are programmed to:

- Identify the subscriber to the network.
- Handle network authentication.
- Provide data storage for basic user data and network information.

#### Benefits of GSM Technology

- Uses encryption to make phone calls secure
- It's easy to change phones; you put your SIM into a new handset and no programming is needed.
- More functionality is available, such as internet access, MP3 player capability, camera capability, etc.

This table lists some of the differences between GSM and CDMA/TDMA technology.

|  | GSM | CDMA / TDMA |
| --- | --- | --- |
| Handset ID | IMEI, International Mobile Equipment ID (burned in) | ESN, Electronic Serial Number (burned in) **or a** MEID, Mobile Equipment ID (14 digits) |
| Subscriber ID | IMSI, International Mobile subscriber ID, on the SIM (15 digits) | MIN, Mobile ID Number (10 digits) |
| SIM ID | ICCID, Integrated Circuit Card ID | N/A |
| Service Number | MSISDN, Mobile Subscriber ISDN | MDN, Mobile Directory Number |
| > [!NOTE] > Note > > The generic term, Service Number is typically used.. |
| Network ID | PMN, Public (Land) Mobile Network, composed of a 3-digit MCC (Mobile Country Code) and a 2 or 3 digit MNC (Mobile Network Code) | SID, System ID (5 digit number) |