eSIM glossary

The world of mobile communications is full of acronyms and seemingly arcane terminology. eSIM technology is a product of this environment so it can be bewildering at first. This glossary is designed to help you get your bearings fast.

APN (Access Point Name)

The APN is all the information your phone uses to connect with your carrier’s network. It lists the address your phone uses to connect to the network, the ports used to handle Multimedia Messaging Service (MMS) messages, the type of data that particular APN uses, and other pieces of information to make sure your phone works correctly.

Bundle

An eSIM Go data connectivity plan.

Carrier File

Network description files managed and held by device manufacturers, containing details on how to set up a connection and work with a given supplier. These are matched to the SIM by the device.

CDR (Call Detail Record)

A line-by-line record of a SIM’s activity including call start/end, caller ID, recipient ID, Call type, Service type, Call charges and device info.

Confirmation code

A code entered by an End User required by the SM-DP+ provider to confirm the download of a Profile.

Consumer

End user of eSIM Go products. Usually the customer of one of our Partners.

Customer

See end user

Device

User equipment used in conjunction with an eUICC to connect to a mobile network. E.g. a tablet, smartphone or handset.

End user

Someone who buys and/or uses eSIM Go products. See also, Customer and Consumer

EID (Embedded Universal Integrated Circuit Card Identifier)

The eUICC identifier is used in the context of remote provisioning and management of the eUICC.

eSIM (Embedded Subscriber Identity Module)

eSIM and eUICC are variations of the software component on a SIM card.

eUICC (embedded UICC)

A UICC enables the remote and/or local management of Profiles in a secure way. UICC is the software component of a SIM card, based on a Tamper Resistant Element (see TRE).

GSMA (Global System for Mobile Association)

GSMA facilitates protocols and standards in mobile technology, from 4G and 5G, to 6G and beyond.

ICCID (Integrated Circuit Card Identifier)

A number assigned to the SIM hardware. A SIM card is essentially an integrated circuit board that is programmed by the mobile operator (MNO or MVNO). The golden part of the SIM is the chipset that the ICCID number is assigned to.

IMSI Number (International Mobile Subscriber Identity)

The telecom company assigns a unique number assigned to the SIM card that they issue to their subscribers. The IMSI numbers are usually 15 digits long (not always though) and can be used to find the subscriber’s country and mobile network, among other SIM-related details. It is tied to the SIM card rather than the phone itself.

IMEI Number (International Mobile Equipment Identity)

Every mobile phone (and new the mobile hotspot dongles) is assigned a unique IMEI number, which is printed on the inside, usually behind the battery pack. They are 15 digits in length. The phone makers allocate unique IMEI numbers to every phone, and these numbers remain unchanged once registered for the rest of its life. So even if you travel to other countries, the telecom operators can identify the Home country of the phone’s sale and registration.

The GSM (Global System for Mobile) Association uses IMEI numbers to store them in a global mobile database which is also central to all network operators, phone makers and other qualified industry parties. While in regular course, the number is useful to identify things like your subscription usage (voice calls, internet) and also determine if there any issues with the quality of services. The IMEI number is as important as the serial number on other products.

LTE (Long Term Evolution)

LTE is a standard for 4G wireless broadband technology that offers increased network capacity and speed to mobile device users. LTE offers higher peak data transfer rates — up to 100 Mbps downstream and 30 Mbps upstream.

MNO (Mobile Network Operator)

Owners and operators of mobile communication networks.

MVNO (Mobile Virtual Network Operator)

MVNOs are carriers that don’t have their own wireless network. They piggyback off another carrier’s platform for coverage through their cell phone plans.

MSISDN (Mobile Station International Subscriber Directory Number)

The full mobile number including the country code and any prefixes.

Multi-IMSI (Multiple International Mobile Subscriber Identities)

Multi-IMSI technology allows the profiles of multiple MNOs to be stored on a single SIM. With multi-IMSI, you often have a single primary MNO.

OTA (Over-The-Air)

A wireless technology used to:

communicate with a SIM card,
download applications to a SIM card,
and manage a SIM card

OTA keys

The credentials included in the profile used in conjunction with OTA platforms.

OTA platform

A platform used by an operator for the remote file/application management of enabled profiles on eUICCs.

PAC (Porting Authorisation Code)

Needed by the end user’s new supplier when they switch.

In the UK can be obtained by texting ‘PAC’ to 65075

Partner

A customer of eSIM Go using our API to resell products to their customers, the ‘end users’ of the product.

Four digit access code for a SIM

Profile

A combination of data and applications to be provisioned on an eUICC for the purpose of providing services. It enables access to a cellular network and influences some aspects of the device behavior on the cellular network.

PUK (Personal Unlocking Key)

Used to unlock a mobile phone. May be needed if

you enter the PIN incorrectly three times
your device is locked to a particular carrier

Roaming

Using cellular service outside of the home network coverage area. The subscriber will be allowed to use a roaming partner’s network.

RSP (Remote SIM Provisioning)

The downloading, installing, enabling, disabling, and deleting of a Profile on an eUICC. Secure and remote (over the air) management of network operator profiles on an eSIM or iSIM.

Secure enclave

A dedicated secure area on a ‘System on Chip’ (SoC), aimed at handling security related workloads and offering self-contained processing and encryption elements. See also TRE

SIM (Subscriber Identity Module)

A unique identifier inside every cellular device, it’s purpose is to verify the identiry of a subscriber and device connecting to a mobile network. The SIM card stores your personal data and may be removable, depending on the device.

SM-DP+ (Subscription Manager Data Preparation Protocol+)

The SM-DP+ address is a unique identifier that specifies the address of the subscription management server used to activate an eSIM
the activation code is a one-time code sent by the service provider, that enables the eSIM to be activated on the device.

SM-DS (Subscription Management Root-Discovery Service)

The universally available platform within the consumer remote SIM provisioning architecture that may be used to inform a eUICC that a profile has been made available for download and on which SM-DP+.

SoC (System on Chip)

A microchip with all the necessary electronic circuits and parts for a given system.

SPN (Service Provider Name) This appears in the top of your phone screen, identifying your service provider.

Subscriber

An entity (associated with one or more users) that has a contract with an operator.

Subscription

Subscription describes the commercial relationship between the subscriber and the service provider.

Subscription management

The ability to move a device from one cellular contract to another by employing remote SIM provisioning.

TRE (Tamper Resistant Element)

A security module consisting of hardware and low-level software providing resistance against software and hardware attacks, capable of securely hosting operating systems together with applications and their confidential and cryptographic data.

UICC (Universal Integrated Circuit Card)

More commonly known as the SIM card, the UICC serves as a subscriber’s identity module.

VoIP (Voice over IP)

A methodology and group of technologies for the delivery of voice communications and multimedia sessions over Internet Protocol networks, such as the internet.

VoLTE (Voice over LTE)

Voice calls over a 4G LTE network.