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Autobiography
Student of Donetsk National Technical University Chudinova Martha

Chudinova Martha

Faculty: Computer information technologies and automation

Department of Automation and Telecommunication

Speciality: Telecommunication systems and networks


Theme of master's work:

Research of a Telecommunication Network of a Mobile Connection with Maintenance of Services at Temporary Abrupt Overload of a Network

Scientific adviser: Turupalov Viktor

Summary

of research and developments

Research of a Telecommunication Network of a Mobile Connection with Maintenance of Services at Temporary Abrupt Overload of a Network

Content

Introduction
  1. A theme urgency
  2. Connection of work with scientific programs, plans, themes
  3. The purpose and problems of the development (research)
  4. Prospective scientific novelty of the received results
  5. Practical value of the received results
  6. Approbation of work results
  7. The rewiew of developements and researches on a theme
  8. The description of the received and planned results ot the work
Conclusions
Bibliofraphy
Note

    Introduction

     Telecommunication networks which use a radio channel as a way of access of the finite user to network services outlive at present time a stage of rapid and wide development. Since 2009 we can see the growth recession of quantity of new subscribers that means glut of mobile services market. Despite of this recession by March, 2010 quantity of subscribers of a mobile communication in the Ukraine is around 112 % of the population.
    Quantity of subscribers (March 2010)
    Киевстар 21.93 millions.
    МТС 17.35 millions.
    Life) 12.16 millions.
    Beeline+GT 1.97 millions.
    I.e. the network of the mobile operator is not insured from overloads and occurrence of peak loadings always is trial for any communication network.

  1. A theme urgency

    2. High level of penetration of cellular communication services in the Ukraine predetermines a growing requirement for maintenance of qualitative mobile communications under certain conditions channels overload of a mobile communication, such as: sharp growth of a network users on sports objects and in large trading complexes, at the airports, on highways. If such overloads are not constants and just unusual occurrences mean that the installation of additional base station is not the optimal decision. In my qualification work I develop recommendations in which will be considering possible examples of overload of mobile networks and optimal approaches for the decision of each chance are described.

  2. Connection of work with scientific programs, plans, themes

    3. Master's qualification work is executed during 2009-2010 agrees with a scientific direction of the department "Automation and Telecommunication" of Automation and Telecommunication.

  3. The purpose and problems of the development (research)

    4. The work purpose: improvement of quality of services granting in mobile networks and maintenance with a stable signal of subscribers at temporary abrupt overload of a network. A problem: the analysis of methods of the decision for purpose achievement. Methodology and methods of researches. For the decision of tasks are used: a mathematical apparatus of probability theory, the theory of mass service, the statistical theory of distribution of radio-waves; methods of mathematical modelling, imitating modelling.

  4. Practical value of the received results

    5. Results of work can be used operators in making decision on development of operating networks of a mobile radio communication of standard GSM and their adjustment. The received results also can be used in the training courses devoted to planning and optimisation of networks of a mobile radio communication of standard GSM.

  5. Approbation of work results

    6. On a theme of qualifying work theses at the Second Student's scientific and technical conference devoted to Day of a science and the World day of telecommunication. Kiev, KPI - 2010 have been printed. At least one more article will be published in September.

  6. The rewiew of developements and researches on a theme


    7. At local level

    In similar works out within university was engaged by M. Soloviov. In his publication «Прогноз трафика GSM с учетом свойств фрактальности» has considered the loading forecast in a mobile communication network. Optimal placing BS for a communication statement has considered in the qualifying work by D. Bukyi "Разработка системы оптимального размещения базовых станций сети мобильной связи стандарта GSM "

    At national level

    In article by Y. Pravik "Методы контроля передачи данных в систесах мобильной связи" is considered variants of efficiency of data transmission, the reason of deterioration of an overall performance of reports. Ways of increase of efficiency of data transmission to mobile networks are offered.

    At global level

    Nikitin's А.в dissertation. (Russian Federation) "Алгоритмы управления радиоресурсами в сетях подвижной радиосвязи стандарта GSM". The essence - consists in working out of methods and algorithms of management of radio network GSM, the statistical data based on use about functioning of a network and providing to users of service of demanded quality in the conditions of the limited hardware and frequency resource. At global level I find the patent of the USA for a theme "Overload control for a central processor in the switching network of mobile communication system", authors: Zhengping Gao, Steve Racz, Kalyan Basu. As on a theme the patent of the Russian Federation authors approaches: Morozjuk V.V.; Muratov E.S. " Способ динамического перераспределения загрузки базовых станций сотовой сети связи и устройство для его осуществления (варианты)", which essence consists that one or several active duplex repeaters of signals to donor (i.e. temporarily not finished loading) to base stations connect.

  7. The description of the received and planned results ot the work

The cellular network is a typical example of queueing system. At it there are all characteristics queueing system necessary for it: a casual stream of demands, duration of a call (duration of employment of a radio channel), final number of service of the channels given to mobile subscribers of a cellular network. The greatest interest, from the point of view of queueing system, represents model for calculation of user's loading in соте taking into account concrete parametres of the equipment of base stations. At an estimation of loading and, hence, capacity in cellular networks use widespread Erlang's model for systems with refusals (probability of receipt of a call during the moment when all channels are occupied) [1]
(1);
where Ротк - probability of refusal, Pv - value of loading, Nc - number of channels in system.
Dependence of critical value of probability of refusal on number of channels.
Fig.1 Dependence of critical value of probability of refusal on number of channels
Researches of calculations have confirmed expediency of research of loading at probability of losses from 0.01 till 0.05. Rather small increase of loading leads to sharp growth of probability of refusal, i.e. to service deterioration.
the Number of the radio channels used on 1 BS can be calculated under the formula (2):
(2);
where Nk - the summary number of the frequency channels allocated for development of a cellular communication network in the given place; Ns-number сеторов.
(3);
Where Fk - the strip of frequencies occupied with one frequency channel of system of cellular communication (a frequency rating between channels).
Traffic Loading of cell is define by the loading factor kc = Tc/C, where Tc - the traffic of cell at busy hours (Erl), C - capacity of cell (Erl). At high loading of cell its traffic exceeds nominal capacity: kc> 1. [2]
(4);
where TN - the summary user's loading on a network (Erl). The next step is to overview possinble technology that can be used:
  • Use of UMA(Unlicensed Mobile Access) technology

    • 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.
    Fig.2 UMA technology
    1. 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.
    2. 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.
    3. 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).
    4. 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.
    5. 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.
  • Use of Smart Antennas

    • Smart antennas (also known as adaptive array antennas, multiple antennas and recently MIMO) are antenna arrays with smart signal processing algorithms used to identify spatial signal signature such as the direction of arrival (DOA) of the signal, and use it to calculate beamforming vectors, to track and locate the antenna beam on the mobile/target. The antenna could optionally be any sensor.
    The smart antenna system estimates the direction of arrival of the signal, using techniques such as MUSIC (Multiple Signal Classification)

    Fig.3 Principle of work of Smart Antenna Works (Animation: volume - 16.4 KB, size - 250x250; number of frames - 13)
    Also it's possible to use ArrayComm's IntelliCell® technology. . IntelliCell technology dramatically improves the capacity, coverage, and quality of wireless voice and data networks across all air interface standards. This is accomplished by enhancing propagation, mitigating interference and reducing the need for spectrum. IntelliCell technology utilizes proprietary software and standard antenna arrays to continuously optimize, in real time, the communication channel with every wireless user. Also known as a fully adaptive "smart antenna" solution, IntelliCell technology essentially makes a virtual wire connection with every user.

    Fig.4 Intellicell

  • Cell Splitting

    • Cell Splitting - The process of creating more coverage and capacity in a wireless system by having more than one cell site cover a particular amount of geography. Each cell site covers a smaller area, with lower power MHz and thus offers the ability to reuse frequencies more times in a larger geographic coverage area. Cell splitting consists of decreasing the radii of existing cells and adding new ones. Cell splitting has been one of the principal means by which cellular telephone operators increased the capacity of their networks, and it will also be a standard tactic for broadband wireless operators, although it will be supplemented by NLOS technologies that were not available to cellular operators during the period of greatest growth in cellular networks. Cell splitting should properly be considered a species of cell mapping or planning and refers to a process by which the network operator redetermines the minimum number of cells required to provide the desired coverage and capacity as the network attracts more subscribers.

    Fig.5 Cell splitting
  • Use of Mobile Base Station

    • Mobile base stations of networks of a mobile communication are the installations intended for maintenance of a mobile communication in extreme situations or in the conditions of a time mass congestion of people (for example, at stadium, at a concert, on meeting), placed on the mobile chassis, capable to independent work in field conditions without connection to external sources энергопитания. The Main objective of creation of a similar sort of the unit is mobile communication maintenance in extreme situations or in the conditions of a time mass congestion of people. Base stations of a network of the mobile communication, placed on the mobile chassis, for example, the car, capable to independent work in field conditions without connection to external sources энергопитания. The typical mobile base station on the capacity is equal to capacity standard three-sector БС and is capable to support to 300 additional vocal channels on distance to 10 km (on open district out of a city).

    Conclusions

     The basic possibilities of maintenance of stable working capacity of a network have been considered only, however I wish to note enough wide range of technologies for the decision of a problem of overloads. My work is aimed at maintenance of simplicity of selection necessary метда at different situations of overloads.

    Bibliofraphy
    1. Лившиц Б.С., Пшеничников А.П., Харкевич А.Д. Теория телетрафика . - М.: Связь, 1979. - 224 с.
    2. Никитина А. В. АЛГОРИТМЫ УПРАВЛЕНИЯ РАДИОРЕСУРСАМИ В СЕТЯХ ПОДВИЖНОЙ РАДИОСВЯЗИ СТАНДАРТА GSM [Текст]: диссертации на соискание ученой степени кандидата технических наук / А. в. Никитина. - СПб., 2009
    3. Бабков В.Ю., Никитин А.Н. Системы мобильной связи с кодовым разделение каналов. - СПб:ТРИАДА, 2003 - 239 с.
    4. Electronic source http://www.arraycomm.com/docs/IntelliCellWhitepaper.pdf
      5. IntelliCell®: A Fully Adaptive Approach to Smart Antennas
    5. Ипатов В.П., Орлов В.К. Системы мобильной связи:Учебное пособие для вузов. - М.:Горячая линия - Телеком, 2003, - 272 с.
    6. Electronic source http://www.umatechnology.org/overview/
      7. UMA technology

    Note

     When writing this abstract the master’s qualification work is not completed. Date of final completion of work: December, 1, 2010. Full text of the work and materials on a work theme can be received from the author or his scientific supervisor after that date.