International Fixed Part Equipment Identity

Description

The International Fixed Part Equipment Identity (IFPEI) is a globally unique identifier assigned to the Fixed Part (FP) equipment in a DECT system. In the context of 3GPP specifications, the IFPEI gains relevance within architectures for Fixed Mobile Convergence (FMC), particularly those integrating DECT-based cordless systems with the IP Multimedia Subsystem (IMS). The FP is the base station or network access point of a DECT system, which provides radio connectivity to Portable Parts (PPs), i.e., the cordless handsets. The IFPEI serves as a permanent, factory-programmed hardware identity for this base station equipment.

Architecturally, when a DECT system is integrated into a 3GPP IMS network—a scenario defined for enterprise or residential FMC—the FP acts as an access gateway. It converts DECT radio protocols to SIP and RTP over IP for communication with the IMS core. For the IMS network to recognize, authenticate, and manage this FP equipment, a unique and verifiable identity is required. This is the role of the IFPEI. It is used during the initial registration of the FP with the network, often in conjunction with authentication procedures that may leverage the IFPEI to retrieve security credentials.

The IFPEI is structured according to ITU-T and ETSI DECT standards. Its format is hierarchical, typically comprising a Fixed Part Manufacturer Code (FPMC) and a manufacturer-assigned serial number for the equipment. This structure ensures global uniqueness. Within 3GPP procedures, the IFPEI may be communicated from the FP to network entities like the P-CSCF or an application server during registration. It allows the network to authorize the specific piece of hardware, apply service profiles specific to that FP (e.g., for an enterprise DECT system), and perform lawful interception or equipment blacklisting if necessary. It is a key parameter for anchoring a DECT-based user's service in the IMS, as the user's identity (like a SIP URI) is often associated with the FP/IFPEI they are registered through.

Purpose & Motivation

The IFPEI exists to provide unambiguous equipment identification in DECT systems, a requirement that becomes critical when these systems are integrated into larger, standardized telecom networks like 3GPP IMS. In standalone DECT deployments, identification might be simpler, but for convergence with IMS—enabling services like a single phone number for both mobile and DECT handsets—robust, standardized identification is essential for security, management, and service delivery.

It solves several problems in an FMC context. First, it enables secure network access: the network can authenticate not just the user (via a SIM or credentials in the Portable Part) but also the legitimacy of the access equipment (the Fixed Part) itself, preventing unauthorized base stations from connecting to the operator's IMS. Second, it facilitates accurate service provisioning and billing; the operator knows which specific hardware (e.g., a corporate DECT base station) a user is connected through, allowing for tailored services and accurate location/routing (e.g., for emergency calls). Third, it provides a handle for equipment lifecycle management, including remote diagnostics, software updates targeted to specific FP models, and compliance with regulatory requirements for equipment registration. Its specification within 3GPP standards ensures interoperability between DECT equipment from any manufacturer and 3GPP IMS networks, which was a key goal for Fixed Mobile Convergence initiatives.

Key Features

• Globally unique, permanent identifier for DECT Fixed Part (base station) equipment
• Structured format including a manufacturer code and serial number
• Used for equipment authentication and authorization in 3GPP IMS FMC architectures
• Enables network-based management and service profiling for specific FP hardware
• Supports regulatory functions like lawful interception and equipment identity checking
• Defined in alignment with ITU-T and ETSI DECT standards for consistency

Evolution Across Releases

Defining Specifications