Tanzania : why internet users in Arusha are smiling

LTE (Long Term Evolution) also known as 4G LTE enables ultra-high-speed internet access because it is the cutting-edge fourth-generation (4G) mobile technology standard and represents a step change in evolution from existing wireless technologies such as GSM-2G/GPRS/EDGE and UMTS-3G/3.75G.

4G LTE is the future platform of all online as well as voice and data communication, and its inherently flexible and constantly evolving nature guarantees that it will remain the superior standard in mobile data and voice services for years to come.

“Smile launched in Dar es Salaam on May 16 2013, making Tanzania the first country in Africa to access this revolutionary technology. We are very excited about bringing this technology to Arusha. As a notable international hub that has vast, thriving and dynamic service and tourism sectors and a range of learning institutions, Arusha has so many businesses, organisations and people that will benefit from high speed internet,” said Fiona McGloin, Smile Country Manager for Tanzania and Uganda.

“We at Smile are confident that providing reliable, high speed internet will significantly contribute to the success of Arusha based businesses and also give the people in Arusha a faster, more reliable and cost effective service,” McGloin said.

In Tanzania’s vibrant communications sector, 4G LTE internet now leads the race being six-times faster than 3G and four-times faster than 3.75G. Smile provides an average speed of 6Mbps download and 3Mbps upload.

source: www.itnewsafrica.com

security aspects in UMTS network

Cellular Internet access Yet, security and privacy issues in femtocell-enabled cellular networks, such as UMTS and LTE, still need to be fully addressed by the bodies.we review significant threats to the security and privacy of femtocell-enabled cellular networks. We also propose novel solution directions in order to tackle some of these threats by drawing inspiration from solutions to similar challenges in wireless data networks such as WLANs and mobile ad hoc networks (MANETs).

                               

The use of mobile devices has changed since the advent of digital technologies such as GSM. What started as a voice only service, has been upgraded mobile networks are used by more than 4 billion users worldwide. One effective way to meet the increasing demand for data rates is to deploy femtocells, which are low-power base stations that connect to the mobile operator through the subscriber’s residential to support data traffic as well. With modern smartphones, users are able to browse the Inter-net and obtain services such as ebanking, navigation, social networking and recommendations based on the subscriber’s location. Femtocells, which are low-power and low-range base stations for cellular networks installed by users at their own premises, are believed to meet the surge in data rates that these multimedia and interactive services require. They offload the macrocell network and provide backhaul connections to the cellular operators’ networks through the users’ residential broadband accesses.

Long Term Evolution (LTE) is the mobile network tech-nology for the next generation mobile communications, as defined by the 3rd Generation Partnership Project (3GPP). In addition to features such as increased data-rates, lower latencies and better spectral efficiency, one of the most in-teresting aspects is the radically novel all-IP core network architecture, known as Evolved Packet Core (EPC). LTE is expected to make extensive use of user-installed femtocells, in order to achieve its goals of spectral efficiency and high-speed for a greater number of users. It is clear that the sensitivity and confidentiality of users and data transiting in such digital cellular networks is paramount both to businesses and private users.

The issue of user identity protection was already raised in the early GSM networks, and the solution that has been adopted ever since has never been substantially revisited. With the ongoing migration towards all-IP and femtocell-enabled cellular networks, the legacy solution might not be appropri-ately suited anymore. In fact, GSM, UMTS and LTE standards mandate the use of unlinkable temporary identifiers  to protect the identity of mobile devices at the air interface, but the capillary deployment of femtocells might render this insufficient to guarantee a satisfactory level of protection for the users. TMSIs  are usually unchanged in a given location (or tracking) area, which is composed by up to a hundred adjacent cells, and femtocells could make it possible for malicious users not only to track the movements of mobile subscribers, but due to the low range, to have an unprecedented accuracy as well. For instance, such tracking attacks could be perpetrated by curious employers, in order to monitor whether an employee is visiting a competitor, or by governmental agencies, in order to illegitimately track people’s locations.

Handover and power control in UMTS network

The rapid growth  of mobile and internet users has led towards the development of the third generation of mobile communication systems. The UMTS is a family of 3G mobile networks designed to offer high bandwidth radio access.

Enhanced UMTS is a Umts evolution step, which makes possible an effective high data rate end to end packet based transmission . IST-SEACORN has proposed a set of enhancements to UMTS which include among others advanced modulation and radio transmission techniques improved strategies for IP routing and QOS assurance.

HANDOVER

The handver process is one of the essential means that guarantees user mobility in a mobile communication  network. The concept of mobility is simple.

When a subscriber moves from the coverage area of one cell to another , a new connection with the target cell is set up and the connection of the previous cell is released.

A basic handover process consists of three main phases:

a)     Measurement phase dealing with the mechanics of measuring important parameters.

b)    Decision phase algorithm parameters and handover criteria

c)     Execution dealing with radio resource allocation and handover signaling.

1.     Operating environment

A handoff algorithm needs to be designed with the operating radio environment in mind in order to define the correct parameters needed in the decision phase. Operating environments are usually separated as:

•        Indoor: low speeds and well-defined mobility paths

•        Outdoor: variable speeds and mobility paths that depend on each environment separately.

A further classification of environments can be made according to their cell size:

•        Pico-cellular and micro-cellular environments: characterized by small cells and low transmit powers. In pico-cellular both users and base stations are located indoors, whereas in micro-cellular only outdoor users are considered. The antenna height in a microcellular environment is typically at lamppost level (5m above ground).

•        Macro-cellular environments have large cells (several kilometres) and transmit high output power with the antenna mounted on a high tower above all surrounding rooftops (15m+ above ground).

POWER CONTROL

Power Control has a dual operation. Firstly, it keeps interference at minimum levels by controlling the power transmitted, achieving further to minimize the power consumption at the mobile user (called User Equipment (UE) in UMTS) and the base stations (called Node Bs in UMTS). Secondly, it ensures an adequate quality of service (QoS) level so that the percentage of dropped calls is kept below the acceptable thresholds.

Power Control is important both in the uplink and the downlink directions. In the uplink direction control is required in the situations where UEs are located very close to the Node Bs and are transmitting with excessive power. This is called the near-far effect and can result in blocking the whole cell, with UEs that are close to the cell edge possibly overlooked. If the uplink power is too high interference in neighbouring cells (inter-cell interference) may also be a direct result of the near-far effect. In the downlink direction, Power Control directly affects system capacity. System capacity is determined by the total downlink transmission power for each cell i.e. when total downlink transmission power is minimized then the Node B can accept more UEs and the capacity is increased.

UMTS services

The best known new feature of UMTS is higher user bit rates: on circuit-switched con-nections 384 kbps, and on packet-switched connections up to 2 Mbps, can be reached. Higher bit rates naturally facilitate some new services, such as video telephony and quick downloading of data. If there is to be a killer application, it is most likely to be quick access to information and its filtering appropriate to the location of a user. Often the requested information is on the Internet, which calls for effective handling of TCP/UDP/IP traffic in the UMTS network. At the start of the UMTS era almost all traffic will be voice, but later the share of data will increase. It is, however, difficult to predict the pace at which the share of data will start to dominate the overall traffic volume. At the same time that transition from voice to data occurs, traffic will move from circuit-switched connections to packet-switched connections. At the start of UMTS service not all of the Quality of Service (QoS) functions will be implemented, and therefore delay-critical applications such as speech and video telephony will be carried on circuit-switched bearers. Later, it will be possible to support delay-critical services as packet data with QoS functions.

universal mobile telecommunications systems

 UMTS is an umbrella term for the third generation radio technologies developed within 3GPP.

The radio access specifications provide for Frequency Division Duplex (FDD) and Time Division Duplex (TDD) variants, and several chip rates are provided for in the TDD option, allowing UTRA technology to operate in a wide range of bands and co-exist with other radio access technologies.

UMTS includes the original W-CDMA scheme using paired or unpaired 5 MHz wide channels in globally agreed bandwidth around 2 GHz, though subsequently, further bandwidth has been allocated by the ITU on a regional basis.

                                                              

W-CDMA was specified in Release 99 and Release 4 of the specifications. High Speed Packet Access (HSPA) was introduced in Releases 5 (Downlink) and 6 (Uplink) giving substantially greater bit rates and improving packet-switched applications.

UMTS is not just about radio: the radio access network connects to the core network which is an evolution from the GSM core. 3GPP has expanded its capabilities, in principle allowing most services to be delivered over either 2G GERAN (GSM/EDGE) or 3G UTRAN.

The core network is becoming progressively access-agnostic, allowing home base stations serving pica-cells to connect directly to the core network via subscribers’ ASDL lines.

3GPP is now working on Long Term Evolution (LTE), which will build on UMTS, as the Industry looks beyond 3G.

Just as GSM has become synonymous with the whole mobile system for 2G, UMTS is 3G, which includes the whole of the W-CDMA and HSPA specifications catalogue.