Transcript Unlicensed Mobile Access

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 802.11 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 .

UNC
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.
Cellular /UMA
How UMA Technology Works

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).
Roaming

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.
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

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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.
Unlicensed Mobile Access (UMA)
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.
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.