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Femto_cells

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It was about Femto cells . When we have a major problems in wireless communication and there is a weak signal received by mobile station , we talk about femto cell which overcome this obstacle and cover a specific area that have the weak signal .

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  1. 1. • Deyaa Ahmed Shaaban • Omar Adel • Omar Hisham • Ahmed Roushdy Saleh
  2. 2. Before we know what Femtocell is, we must know Why we searched for it …..!!!
  3. 3. The growing number of cellular network users raises issues about coverage extension in some areas such as indoor or underground locations. Why is there a need for such small cells? The most efficient way to increase network capacity in a cellular network is to shrink the cell size– ok, there are other ways, including getting new spectrum, sectorization, adaptive algorithms for scheduling but all are semi-disruptive and cannot compete with a smaller cell size. However, in an archetypal mobile network, the cost to deploy a network with many small cells in data hungry areas is prohibitive. Femto cells piggyback on broadband connections and are relatively inexpensive and can effectively form a distributed high capacity network. On a much simpler usage case, femto cells can provide coverage where ordinary cells cannot, in highly populated areas where propagation issues are a concern.
  4. 4. Femtocell is a low-power wireless base station for cellular access indoor in areas with limited or no cellular provider. The access point operates in a licensed spectrum and is designed to route mobile phone traffic through a home or corporate IP network. A femtocell is connected to a broadband (cable modem or Digital Subscriber Line) and provides complete voice and data service to standard mobile devices such as cell phones with al limited number and within a limited range. It supports 2 to 5 mobiles.
  5. 5. Unique Characteristics of Femtocells • Designed for the home environment – Might get deployed in small-office/home-office or business situations, but this is not the primary design target • Operate in licensed spectrum – E.g., WiFi-based fixed mobile convergence solutions are not femtocells – Therefore, femtocells must be operated or associated with a spectrum license holder • Designed to connect to the operator’s network via an untrusted broadband IP-based network, typically public – E.g., Cable, DSL, or other home broadband service – Does not preclude usage over private IP networks or even non-IP networks, but that is not the design target
  6. 6. Capabilities and Services High level goal: The end user has access to all capabilities of his/her mobile device. • Voice calling (outbound and inbound) • Additional services such as 3-way calling, call hold, caller-ID, etc. • Messaging (such as Text and picture messages or other multimedia messaging services) • Data services (such as mobile broadband access) • Broadcast services • Location services (and location-based services, navigation applications, etc.) • Emergency services (such as E911)
  7. 7. Potential End User Benefits • Improved coverage in their home • Possibly just providing coverage where there is none! • Enhanced availability of services • Possible incentives from carriers (e.g., reduced rates or flat-rate services in the “home zone”) • Ability to use mobile device as primary “phone” • Availability of richer cellular services while at home • Improved battery life while at home
  8. 8. We will handle two challenges : • RF interference (inter-femto, macro-femto) • Handoff
  9. 9. RF Interference • Areas of concern: – Femtocell to macrocells – Femtocell to femtocell • May be partially avoided if femtocells can be deployed in different radio channels from macro system • Unlikely that femtocell to femtocell interference can be managed via unique radio channel assignments – Eventually femtocell density will make this impossible • In general, standards must provide ways to operate femtocells in common radio channels with macro
  10. 10. Solutions for RF Interference • Most aspects of RF interference mitigation will likely be addressed by proprietary solutions • Radio resources must be assigned using centralized planning – Radio channel for operation of each technology – PN codes – Power control parameters, transmission power limits, etc. – Requires accurate knowledge of deployed femtocell locations, capabilities, and other feedback information from all femtocells to the centralized femtocell management system • Femtocells must utilize techniques to reduce interference autonomously and continuously – Based on feedback and measurements about the RF environment – Based on feedback from MS/ATs (e.g., pilot reports)
  11. 11. Handoff • Types of handoff: – Handout from femtocell to macro system – Handin from macro system to femtocell – Inter-femtocell handoff between femtocells • Inter-femtocell handoff is generally not required for home-based femtocells (at least for early deployments) – May be required as the technology involves to be used in enterprises (e.g., picocells) • Packet data service handoff follows normal packet data mobility procedures (e.g., Mobile IP)
  12. 12. Solutions for Handoff • Handout from femtocell to macro system is fairly straightforward: – MS reports macro system pilots to the femtocell – Femtocell triggers handoff to macro system via standard ANSI-41 IS handoff signaling to target MSC • For legacy circuit architecture, A1p triggers controller to initiate ANSI-41 IS handoff • For SIP/IMS architecture, SIP signaling triggers CSRV to initiate ANSI-41 IS handoff – When target MSC responds with handoff parameters, the information is passed back to the femtocell – Femtocell sends handoff direction message to mobile directing it to the macro system directly – Call continues
  13. 13. Radio health issues research A very large amount of research has been undertaken into discovering any links between low level radio frequency radiation and health issues. If any major links had been found, then it should be a safe assumption that legislation would have been altered and the use of low power radio changed. Much of the research that has been undertaken has been statistical in nature. Research would look at users of radio equipment and those who have a much lower level of usage, or no usage at all. The results have to be interpreted in a statistical nature, because some people who are not exposed to radiation will fall ill anyway. Therefore it is necessary to look at the illnesses that occur in the two groups of people. Even with large samples, it appears that most research projects have found little or no evidence of major health risks and therefore the health organisations have been willing to allow the current levels of radiation in and around the home.
  14. 14. Although no direct links to cancer have been found, it is a recognised fact that radio frequency radiation does heat up local tissue - in the same way as a microwave oven works, although the power levels for microwave ovens are much higher. As a result a phenomenon known as "hot ear" can occur when a cell phone held close to the ear is used for an extended period of time. It is therefore recommended that cellphones are not used for extended periods of the day. However, it is current thinking that in view of the 1/d^2 law where power reduces as the square of the distance, means that femtocells should not pose any form of risk.
  15. 15. Femtocells are cellular base stations roughly the size of a Wi-Fi router. Their diminutive size belies the market opportunity for apps that use femtos to enable services that otherwise would be difficult or impossible with other technologies. Many mobile operators and vendors believe that small cells will be key for delivering the multi-megabit speeds that customers expect from 4G/LTE while reducing traffic loads on the outdoor sites. The market opportunity for femto apps depends partly on the installed base of femtos. Currently there are more than 6 million femtocells and other small cells installed worldwide Although that’s already more than the number of macrocells, collectively it’s still a tiny addressable market because each small cell serves only a handful of potential mobile app customers.
  16. 16. That will change as small cell deployments continue to mushroom, according to analyst predictions. In the meantime, finding the market opportunities for app development means focusing on what specific operators are doing. “I’d say maybe half a dozen to a dozen commercial apps today,” Germano says. “We’re at the early stage of the market where what we’ll see is a little more mobile operator involvement in new small- cell-based applications. Some of these applications will be unique to specific operators or for specific enterprise customers.”
  17. 17. • http://www.airvana.com/technology/femtocell-network- architecture/#Intro • http://www.radio- electronics.com/info/cellulartelecomms/femtocells/femto-cells-health- issues.php • http://en.wikipedia.org/wiki/Femtocell

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