UMA (Unlicensed Mobile Access) El Ayoubi Ahmed Hjiaj Karim

Unlicensed Mobile Access (UMA) Unlicensed Mobile Access (UMA) technology provides access to GSM and GPRS mobile services over wireless networks based on unlicensed spectrum technologies, e.g. Bluetooth and IEEE networks. By deploying UMA technology, service providers can enable subscribers to roam and perform seamless handovers between cellular networks and public and private unlicensed wireless networks, and to use for instance SIM/AuC authentication also in the wireless networks, using dual-mode handsets.

Roaming vs. portability Roaming means that it is possible to use a terminal when moving from one network to another. Additional features (mobility, security) that involve cooperation between network operators or service providers are usually supported, due to roaming agreements between these operators or service providers. Portability means that it is possible to use a terminal anywhere in a certain network (e.g. WLAN). However, when moving to another network, mobility or security features are not automatically maintained.

Terminal vs. personal mobility Terminal mobility means the ability of the network to locate a mobile terminal, route incoming or outgoing calls (or packet sessions) regardless of the point of attachment to the network, and maintain connections while the terminal moves around in the network. Personal mobility means that a person can be reached via any one of several terminals (that can be located at different places) using a single address (e.g. SIP address). This concept has not been widely used yet.

UMA Protocols UMA is on top of it at the transport layer (Layer 4) and has its own set of control protocols.

 The UMA specification is based around UNC. What is UNC??? A UMA Network Controller (UNC) acts as a virtual base station, providing handoff between cellular and Wi-Fi networks. UNC

Cellular /UMA

A mobile subscriber with a UMA-enabled, dual-mode handset moves within range of an unlicensed wireless network to which the handset is allowed to connect. Upon connecting, the handset contacts the UMA Network Controller (UNC) over the broadband IP access network to be authenticated and authorized to access GSM voice and GPRS data services via the unlicensed wireless network. How UMA Technology Works

If approved, the subscriber’s current location information stored in the core network is updated, and from that point on all mobile voice and data traffic is routed to the handset via the Unlicensed Mobile Access Network (UMAN) rather than the cellular radio access network (RAN). When a UMA-enabled subscriber moves outside the range of an unlicensed wireless network to which they are connected, the UNC and handset facilitate roaming back to the licensed outdoor network. This roaming process is completely transparent to the subscriber. Roaming How UMA Technology Works Roaming How UMA Technology Works

Handover  Handover in: The mobile station moves from macro network to a UMAN.  Handover out: The mobile station moves from UMAN to macro network.  Handover UMA: The mobile station moves with in a UMAN or from UMAN to UMAN.

Handoff Specifications  Subject to mode selection, UMA shall support seamless handover in and handover out,provided the following conditions are true:  The mobile station stays within the limits of service (pedestrian state of motion)  The mobile station remains during the time of handover within the coverage of both the networks.  UMA shall manage bandwidth during handover between macro network and UMAN.

UMA Functional Architecture

Security in UMA Different security mechanism operate at different levels: MS to AP – UMA does not mandate any security mechanism, but can coexist with available one. MS to UNC – The UNC includes a security gateway that provides mutual authentication and encryption for the traffic across the WLAN and the broadband connection. MS to core mobile network – The encryption and authentication methods used by the MS when using the GERAN are also used to protect UMA connections. MS to application server – An additional end-to-end data application mechanism (for example, HTTPS) may be used if needed.

Advantages Availability & Pricing  UMA could be used to provide better in-building coverage for customers who don't get a good cellular signal in some areas, including basements.  It enables service providers to deliver voice at a lower cost when handsets are within range of an unlicensed wireless network.  If a customer doesn't have a wireless network already in the house, a wireless access point would be needed in addition to a broadband link.  The most expensive and technologically challenging component of UMA solution is the Wi-Fi and cellular handset, because of battery-life limitations, cost, and size.  UMA cannot guarantee the quality of a voice call or the throughput of a data connection and traffic prioritization with QoS can significantly improve performance.

In order to promote the widespread adoption of UMA technology, a number of companies within the cellular & wireless industry have jointly developed a set of open specifications. Unlicensed Mobile Access (UMA) UMA lets mobile operators deliver voice, data and IMS/SIP(IP Multi media Subsystem /Session Initiated Protocol) applications to mobile phones on Wi-Fi access network using dual-mode mobile handsets.

Unlicensed Mobile Access (UMA ) What is needed to implement UMA infrastructure? 1. UMA-capable terminals 2. UMA network controller 3. Protocols that offer secure transport of GSM/GPRS signalling and user plane traffic over IP.