UNLICENSED MOBILE ACCESS/GENERIC ACCESS NETWORK: Possible Impact in Pakistan to Provide Cost-Effective 3G Solution: Syed Bilal Raza Tirmizi

ABSTRACT:

The popularity of wireless communication systems can be seen almost every where in the form of cellular networks, WLANs, and WPANs. In addition small portable devices have been increasingly equipped with the multiple communication interfaces building a heterogeneous environment in terms of access technologies. This has motivated researchers to integrate various wireless platforms such as cellular networks, WLANs etc. The desired ubiquitous computing environment of the future has to exploit this multitude of connectivity alternatives resulting from diverse wireless communication systems and different access technologies to provide useful services with guaranteed quality to users. The research presented in this paper explores the concept of Unlicensed Mobile Access (UMA)/Generic Access Networks (GAN) and its possible impact, its economic and commercial feasibility for both the service providers and the consumers and proposed suggestions and finally it discuss the cellular operators’ approach for the deployment of 3G in Pakistan.

1. INTRODUCTION:

UMA/GAN is 3rd generation partnership project (3GPP) [1] global standard for subscribers access to mobile circuit, packet and IP Multimedia Subsystem (IMS)-based services over an IP-based access network, including the internet. With UMA/GAN, mobile operators can now leverage the cost and performance advantages of IP access technologies (DSL, Cable, Wi-Fi…) to deliver high-quality, low-cost mobile voice and data services in the location where subscriber spend most of their time at the home and office [2].
The local network may be based on private unlicensed spectrum technologies like Bluetooth or 802.11, while the wide network is alternatively GSM/GPRS or UMTS mobile services. On the cellular network, the mobile handset communicates over the air with a Base station, through a Base Station Controller to servers in the core network of the carrier. Under the UMA/GAN system, when the handset detects a LAN, it establishes a secure IP connection through a gateway to a server called a UMA/GAN controller on the carrier network. The architecture of UMA/GAN is shown in FIGURE 1.

The UMA/GAN controller translates the signals coming from the handset to make it appear to be coming from another Base Station. Thus, when a mobile moves from a GSM to an 802.11 network it appears to the core network as if it is simply on a different BTS [4].

2. AVAILABLE TECHNOLOGIES AND CELLULAR GROWTH IN PAKISTAN:

Pakistan has seen major and rapid technological advancements in recent years in IT and telecom sector with 58.8% teledensity having growth of 30.6% [5]. At present wireless and cellular technologies available in Pakistan are GSM, GPRS, EDGE, CDMA2000, Wi-Fi [6] and Wimax [6]. Pakistan has been one of the fastest growing mobile markets among the emerging telecom markets. Subscription of subscribers remained impressive throughout and all companies together added more than 25 million subscribers to their networks. Total subscribers crossed 88 million at the end of 2007-08 [5]. At present there are more than 90 million cellular subscribers in Pakistan.

3. UMA/GAN’s POSSIBLE IMPACT IN PAKISTAN:

The world is in the middle of the economic crises and Pakistan has also faced the economic problems due to the problems in the South Asian region. The economy registered a growth of 5.8% in 2008 against the target of 7.2% [5]. In relation to slow economic growth the telecom sector also exhibited slow growth trend. While companies finding difficult to maintain and enhance existing networks, UMA/GAN can play a role in not only in maintaining the network but can also help in extending the services specially to those areas where quality of service is not good for any reasons or to very thinly populated areas where installing Base Stations are not good economical and commercially feasible option. UMA/GAN offers benefits for both the operators and consumers simultaneously and can play a major role in future developments in telecom industry along with other 3G technologies. Some of the advantages of UMA/GAN for service providers are:
• Instead of erecting expensive base stations to cover every nook and cranny of a neighborhood, GAN allows carriers to add coverage using low cost 802.11 access points. When at home, subscribers have very good coverage.
• In addition, GAN relieves congestion on the GSM or UMTS spectrum by removing
common types of calls and routing them to the operator via the relatively low cost Internet.
• GAN makes sense for network operators that also offer internet services. Operators can leverage sales of one to promote the other, and can bill both to each customer.
• At the same time UMA/GAN also offers economic & quality of service based benefit to Customer which can focus the thinly populated or highly congested areas for converge and quality of service to the customers of average income base in Pakistan especially small towns and remote villages.
UMA/GAN offered benefits to subscribers are:
• Subscribers do not rely on their operator’s ability to roll out towers and coverage,
allowing them to fix some type of coverage black spot themselves (such as in home or office).
• The cheaper rates of 802.11 use, coupled with better coverage at home, make it more affordable and practical to use cell phones instead of landlines.
• UMA/GAN is the only technology available that combines GSM and 802.11 into a Service that uses a single number, a single handset, single set of services and single phone directory for all calls [7].

4. PAKISTAN’S APPROACH AND PROPOSED SUGGESTIONS:

Pakistan now has a higher concentration of cellular networks with amazing services like GPRS, voice and message services at competitive rates besides multimedia messages and much more. But, all that probably is nothing compared to what has been brewing in the cellular sector. Cellular giants are preparing to spice things up under a single roof, with 3G. According to Telenor, Pakistan” Time for 3G is now” [8]. Echoing along similar lines Ufone also saw time ripe for 3G. Ufone was the view that broadband market had witnessed a significant growth in last 12 months, crossing 200,000 subscribers with the launch of wireless broadband service [8]. With WCDMA and UMTS [9] are other emerging technologies one of the reasons to prefer UMA/GAN over WCDMA or UMTS is that the introduction of UMA/GAN by a network operator is relatively low cost and straight forward. While WCDMA and UMTS requires relatively expensive and complicated backhaul circuits as well as costly Base Stations. The estimated cost of UMTS, GSM and UMA/GAN for covering approximately 20 to 30 Km

Also UMTS deployment has two main limitations with regards to its capability to deliver cost effective high speed mobile broadband, (1) its relatively poor in-building penetration and (2) its limited coverage capability compared to lower frequencies [10]. Whereas UMA/GAN only requires the users to additionally utilize their existing broadband connections. Also UMA/GAN is compatible with UMTS, so future deployment and extension of UMTS network will be relatively cheaper with better indoor coverage [11]. With cellular companies currently focusing on investing in remote areas to connect un-served people, UMA/GAN can be the proper solution.

5. CONCLUSION:

If WLAN access support to existing service set is in focus e.g. for home zone tariffs, or better indoor coverage, then UMA/GAN is the perfect match. UMA/GAN is an access near solution with no impact on offer services. With telecom and cellular industry evolving so rapidly, 3G in Pakistan is not a distant dream. The issues like integration of existing 2.5g (GSM) network with 3G networks can duly addressed by UMA/GAN as its is compatible with GSM. Cellular operators in Pakistan can adapt this technology to enhancing their networks to 3G without replacing the existing infrastructure and also can extend their network coverage including very remote and far areas with avoiding the costly BTS installations. With UMA/GAN, a low cost and commercially acceptable deployment of 2G/3G networks is possible.

REFERENCES:

[1] www.3gpp.org
[2] “Kineto Wireless” press release 7th February 2006
[3] “Norsk UMTS-forum” 24th Jan 2007 by ERICSSON
[4] “Issues in integrating cellular networks, WLANs and MANETs: A futuristic Heterogeneous Wireless Network” by Dave cavalcanti, Dharma Agarwal, University of Cincinnati. Carlos Cardeiro, Philips Research USA. Bin Xie & Anup Kumar, University of Louisville.
[5] Annual Report 2008 by Pakistan Telecommunication Authority
[6] IEEE standards (802.11 & 802.16)
[7] www.umatechnology.org
[8] “Flare Magazine” Mar-Apr 2009 Issue
[9] www.UMTSforum.org
[10] Position Paper UMTS/HSXPA by Motorola Inc
[11] “Generic & Open Media Access for Next Generation Wireless Networks: A case study” by Mahesh Sooriyabandara, Member IEEE

How Satellites Work

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Fiber Optics Basics

Fiber optic technology is simply the use of light to transmit data. The
general use of fiber optics did not begin until the 1970s. Robert Maurer of
Corning Glass Works developed a fiber with a loss of 20 dB/km,
promoting the commercial use of fiber. Since that time the use of fiber
optics has increased dramatically. Advances in fiber technology, lower
production costs, and installation have all contributed to the wide use of
fiber.
The purpose of this paper is to provide an overview of fiber, its
construction, and functionality.
The heaviest use of fiber is in the telecommunications industry. Telephone
companies initially used fiber to transport high volumes of voice traffic
between central office locations. During the 1980s telephone companies
began to deploy fiber throughout their networks. Fiber technology allows
companies to "future proof" networks. We use the phrase "future proof"
because fiber is theoretically unlimited in bandwidth. Bandwidth is a
measurement of the data carrying capacity of the media (in this case,
fiber). The greater the bandwidth, the more data or information that can
be transmitted. Copper has a bandwidth and a distance limitation,
making it less desirable.
Benefits of fiber include:
„ High bandwidth for voice, video and data applications
„ Optical fiber can carry thousands of times more information than
copper wire. For example, a single-strand fiber strand could carry all
the telephone conversations in the United States at peak hour
„ Fiber is more lightweight than copper. Copper cable equals
approximately 80 lbs./1000 feet while fiber weighs about 9
lbs./1000 feet
„ Low loss. The higher frequency, the greater the signal loss using
copper cabling. With fiber, the signal loss is the same across
frequencies, except at the very highest frequencies
„ Reliability - Fiber is more reliable than copper and has a longer life
span
„ Secure - Fiber does not emit electromagnetic interference and is
difficult to tap
Optical fiber is composed of several elements. The construction of a fiber
optic cable consists of a core, cladding, coating buffer, strength member
and outer jacket. The optic core is the light-carrying element at the center.
The core is usually made up of a combination of silica and germania.
The cladding surrounding the core is made of pure silica. The cladding
has a slightly lower index of refraction than the core. The lower refractive
index causes the light in the core to reflect off the cladding and stay
within the core.
Index of refraction is the ratio of the velocity of light in a vacuum to the
velocity of light in a material. The speed of light in a vacuum is equal to
300,000,000 meters per second.The higher the index of refraction, the
slower the speed of light through the material.
Index of Refraction = Light velocity (vacuum)
Light velocity (material)
For example:
Air = 300,000,000 meters/second
IR = 1
Glass = 200,000,000 meters/second
IR = 1.5
Fiber is either single mode or multimode. Fiber sizes are expressed by
using two numbers: 8/125. The first number refers to the core size in
microns. The second number refers to the core size plus the cladding size
combined

UMA Overview

Unlicensed Mobile Access (UMA) technology provides access to GSM and GPRS mobile services over unlicensed spectrum technologies, including Bluetooth and 802.11. By deploying UMA technology, service providers can enable subscribers to roam and handover between cellular networks and public and private unlicensed wireless networks using dual-mode mobile handsets. With UMA, subscribers receive a consistent user experience for their mobile voice and data services as they transition between networks.

In order to promote the widespread adoption of UMA technology, a number of leading companies within the wireless industry have jointly developed a set of open specifications. These specifications are available through this Web site, and may be used by vendors and carriers of wireless communications systems and applications to develop and deploy interoperable solutions.

In addition to developing and maintaining the initial specifications, the participating companies are actively working with the 3GPP standards organization to use the specifications as the basis for the development of a formal standard.

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.
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: If a subscriber is on an active GSM voice call or GPRS data session when they come within range (or out of range) of an unlicensed wireless network, that voice call or data session can automatically handover between access networks with no discernable service interruption. Handovers are completely transparent to the subscriber.

Telecommunications engineering

Telecommunications engineering or telecom engineering is a major field within Electronic engineering. The work ranges from basic circuit design to strategic mass developments. A telecommunication engineer is responsible for designing and overseeing the installation of telecommunications equipment and facilities, such as complex electronic switching systems, copper telephone facilities, and fiber optics. Telecom engineering also overlaps heavily with broadcast engineering.
Telecommunication is a diverse field of engineering including electronics, civil, structural, and electrical engineering as well as being a political and social ambassador, a little bit of accounting and a lot of project management. Ultimately, telecom engineers are responsible for providing the method that customers can get telephone and high speed data services.
Telecom engineers use a variety of different equipment and transport media available from a multitude of manufacturers to design the telecom network infrastructure. The most common media, often referred to as plant in the telecom industry, used by telecommunications companies today are copper, coaxial cable, fiber, and radio.
Telecom engineers are often expected, as most engineers are, to provide the best solution possible for the lowest cost to the company. This often leads to creative solutions to problems that often would have been designed differently without the budget constraints dictated by modern society. In the earlier days of the telecom industry massive amounts of cable were placed that were never used or have been replaced by modern technology such as fiber optic cable and digital multiplexing techniques.
Telecom engineers are also responsible for keeping the records of the companies’ equipment and facilities and assigning appropriate accounting codes for purposes of taxes and maintenance. As telecom engineers responsible for budgeting and overseeing projects and keeping records of equipment, facilities and plant the telecom engineer is not only an engineer but an accounting assistant or bookkeeper (if not an accountant) and a project manager as well.
This article provides an overview of the major field, telecommunications engineering. Readers might be interested to have a look at electronic engineering and broadcast engineering which are heavily related to telecommunications engineering and often taught together in different academic institutes.