Femtocells

PowerPoint Presentation

Femtocell26/05/2015

Samin Amin Ramay Tanvir Raihan Geysung Choi Faculty of Engineering and IT, University of Technology Sydney [email protected]@[email protected]

26/05/15149048. Femtocells. Geysung Choi/ Tanvir Raihan/ Samin Amin Ramay Supervisor A/Prof Sandy K.Sandrasegaran 1Presentation OutlineWhat is FemtocellHow Femtocell WorksBenefits of FemtocellStandardization of FemtocellDeployment Model of FemtocellsTechnical Challenges of FemtocellAccess MechanismsClosed AccessOpen AccessHybrid AccessInterference Managements Mobility Management and HandoverComparision of Femtocells & Wi-Fi

26/05/15249048. Femtocells. Geysung Choi/ Tanvir Raihan/ Samin Amin Ramay Supervisor A/Prof Sandy K.Sandrasegaran 2What is Femtocell26/05/153

Figure 1. What is FemtocellsVia http://www.mvnodynamics.com/definition-subscriber-identification-module-sim/definitions-femtocell/49048. Femtocells. Geysung Choi/ Tanvir Raihan/ Samin Amin Ramay Supervisor A/Prof Sandy K.Sandrasegaran Femtocells are low-power wireless access points that operate within the licensed spectrum to connect standard mobile devices to a mobile operators network using existing DSL or cable broadband connections. The base station of Femtocell is also known as Home Node B (HNB) for UMTS Home eNode B (HeNB) for LTE Femtocell Access Point (FAP)

Femtocells are sold by amobile network operator(MNO) to its residential or enterprise customers. A femtocell is typically the size of aresidential gatewayor smaller, and connects to the usersbroadbandline. Integrated femtocells which include both a DSL router and femtocell also exist. Once plugged in, the femtocell connects to the MNOs mobile network, and provides extra coverage. From a users perspective, it isplug and play, there is no specific installation or technical knowledge requiredanyone can install a femtocell at home [2].

Femtocells are an alternative way to deliver the benefits offixed-mobile convergence (FMC). The distinction is that most FMC architectures require a new (dual-mode) handset which works with existing unlicensed spectrum home/enterprisewireless access points, while a femtocell-based deployment will work with existing handsets but requires installation of a new access point that uses licensed spectrum [2].

3What is Femtocell26/05/154

Users and CoverageFigure 2. Users and CoverageVia http://www.slideshare.net/zahidtg/how-wifi-and-femtocells-complement-one-another-to-optimise-coverage-and-capacity49048. Femtocells. Geysung Choi/ Tanvir Raihan/ Samin Amin Ramay Supervisor A/Prof Sandy K.Sandrasegaran The range of astandard base stationmay be up to 35 kilometres (22mi), amicrocellis less than two kilometers wide, ametro is 200 meters or less, and a femtocell is in the order of 10 meters and cover 2- 8 User [1].

4How Femtocell Works

26/05/155Figure 3. Femtocell Access to the Core Mobile Network via Broadband InternetVia https://www.juniper.net/techpubs/software/aaa_802/imsaaa11/sw-imsaaa-admin/html/Overview3.html49048. Femtocells. Geysung Choi/ Tanvir Raihan/ Samin Amin Ramay Supervisor A/Prof Sandy K.Sandrasegaran The user must then declare which mobile phone numbers are allowed to connect to his femtocell, usually via a web interface provided by the MNO.This needs to be done only once. When these mobile phones arrive under coverage of the femtocell, they switch over from themacrocell (outdoor) to the femtocell automatically. Most MNOs provide a way for the user to know this has happened, for example by having a different network name appear on the mobile phone. All communications will then automatically go through the femtocell. When the user leaves the femtocell coverage area, his phone hands over seamlessly to the macro network [3].

The mobile operators telephone switch (MSC) and data switch (SGSN) also communicate to the femtocell gateway in the same way as for other mobile calls. Therefore, all services including phone numbers, call diversion, voicemail etc. all operate in exactly the same way and appear the same to the end user.

The mobile operators telephone switch (MSC) and data switch (SGSN) also communicate to the femtocell gateway in the same way as for other mobile calls. Therefore, all services including phone numbers, call diversion, voicemail etc. all operate in exactly the same way and appear the same to the end user [3].

Inside the femtocell are the complete workings of a mobile phone basestation. Additional functions are also included such as some of the RNC (Radio Network Controller) processing, which would normally reside at the mobile switching centre. Some femtocells also include core network element so that data sessions can be managed locally without needing to flow back through the operators switching centres.

5Benefits of Femtocell26/05/156For Network OperatorsFor SubscribersImproved Network CoverageReduced In Home Call ChargesReduced Backhaul CostImproved Indoor CoverageIncreased Subscriber CapacityImproved Broadband Experience Improved Customer RetentionWorks with Existing HandsetsIncreased Revenue OpportunitiesReduced Mobile Battery DrainAddresses VOIP ThreatsNew Converged ServicesStimulates 3G UsageOne Consolidated BillTable1. Benefits of FemtocellVia http://tr.nec.com/en_TR/global/solutions/nsp/3g/products_and_solutions/prod_femtocell/benefits/index.html49048. Femtocells. Geysung Choi/ Tanvir Raihan/ Samin Amin Ramay Supervisor A/Prof Sandy K.Sandrasegaran Radio equipment costs [5] Use the extremely cost-optimized design of thefemtocell access point Require no new Users Equipment (UE)Installation and deployment costsOperation and maintenance and

Radio equipment costs Use the extremely cost-optimized design of thefemtocell access point Require no new Users Equipment (UE)Installation and deployment costsOperation and maintenance and

Infrastructure and Cost Reduction Backhauling costs Utilize the existing public Internet for backhauls Off-load the traffic from the macrocell network

Power Reduction Transmission uses less power because it requires covering ashort radius of cells Benefits Extending battery lifetime Reducing inter-cell interference Increasing the SINR Improving the signal reception

Power Reduction [4]. Transmission uses less power because it requires covering ashort radius of cells Benefits Extending battery lifetime Reducing inter-cell interference Increasing the SINR Improving the signal reception

Key benefits for operatorsImprove 3G coverage indoors by having accesspoint.Create network capacity wherever needed.Improve macro network QoS by offloading traffic.Reduce cost of service delivery through use of subscriber assets such as DSL, site and power.Improved QoS and lower tariffs - enhancing customer retention and reducing churn.Enhanced acquisition through capturing whole families on the network.Further stimulate premium data services by removing cost and convenience barrier at home

6Standardization of FemtocellStandards organizations concerned with Femtocells 3GPPUMTS, LTE related Femtocell 3GPP2: CDMA2000 related Femtocell WiMAX Forum: WiMAX related femtocell26/05/157

Figure 4. Standardization of FemtocellVia http://en.wikipedia.org/wiki/Femtocell49048. Femtocells. Geysung Choi/ Tanvir Raihan/ Samin Amin Ramay Supervisor A/Prof Sandy K.Sandrasegaran Femtocell was standardized in 3GPP Release 8 [9]. Home Node B (HNB) in WCDMA system Home e Node B (HeNB) in LTE system

Standard Documents for H(e)NB as follows [10]: Service requirements Architectural aspects IMS aspects of architecture Mobility procedures Radio frequency requirements Operation, Administration, Maintenance and Provisioning (OAM&P) Self Organizing Networks (SON) Security

7Femtocells Deployment Models

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Figure 5. Femtocells Deployment ModelVia Dx Xinning Zhu , Introduction of Femtocells, Powerpoint Slides , UTS ONLINE49048. Femtocells. Geysung Choi/ Tanvir Raihan/ Samin Amin Ramay Supervisor A/Prof Sandy K.Sandrasegaran 8Access Control MechanismsThree Types Of Access Control MechanismsClosed AccessOpen AccessHybrid Access

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Figure 6. Access Control MechanismsVia University of Bedforshire, Access Control mechanism For Femtocells , roche, Valcarce, 200749048. Femtocells. Geysung Choi/ Tanvir Raihan/ Samin Amin Ramay Supervisor A/Prof Sandy K.Sandrasegaran the selection of an access control mechanism for femtocells has dramatic effects on the performance of the overall network, mainly due to its role in the definition of inter- ference. Different approaches have been pro- posed [24] Closed access: Only a subset of users, defined by the femtocell owner, can con- nect to the femtocell. This model is referred to as closed subscriber group (CSG) by the Third Generation Partnership Project (3GPP) [4]. Open access: All customers of the operator have the right to make use of any femtocell. Hybrid access: A limited amount of the fem- tocell resources are available to all users, while the rest are operated in a CSG manner.

9Access Control MechanismsClosed Access Only Specific User can access a femtocellReferred to as CSG (close subscriber Group)Technical Challenged in Closed AccessStrong Cross layer InterferenceCo-layer InterferencePossible Solutions FAP power ControlUse of Sector AntennaOFDMA26/05/151049048. Femtocells. Geysung Choi/ Tanvir Raihan/ Samin Amin Ramay Supervisor A/Prof Sandy K.Sandrasegaran In closed access, only the femtocell subscribers are allowed to connect to the femtocells. Technical Challenges and Solutions In scenarios with CSG FAPs, nonsubscribers are not allowed to connect to the network through a femtocell, even if its signal is stronger than that of the closest macrocell. Therefore, strong cross- tier interference exists between both tiers; for example, femtocells could jam the downlink communication of passing nonsubscribers con- nected to a far macrocell, and nonsubscribers located close to a femtocell could jam the femto- cell uplink. One of the most challenging cases of cross-tier interference in CSG FAPs, in both the downlink and the uplink, occurs when a nonsub- scriber enters a house hosting a CSG femtocell. In this case the power of the interference is much larger than that of the carrier signal. [24] To avoid this worst case scenario, the femtocell owner should authorize guest nonsubscribers in a fast manner so that they gain access to the femtocell. However, the list of authorized users is controlled by the operator, resides in the core network, and has to be manually updated by the femtocell owner. Co-tier interference also comes up between neighboring femtocells in dense deployments. In many cases users will install their femtocells in random positions within their homes (e.g., close to a room of a neighbor or close to a window). In this case subscribers will sometimes be severe- ly jammed by neighboring femtocells, and thus unable to connect. Therefore, solutions are required to reduce both cross-tier and co-tier interference, allowing the deployment of a large number of femtocells within the existing networks. Interference cancel- lation and avoidance techniques for femtocell networks are hence currently an important research topic. In order to guarantee femtocell connectivity and mitigate interference, the power radiated by the FAP must be tuned to ensure sufficient cov- erage to femtocell subscribers and minimize leakage of power outside the premises. [24] This can be done by self-optimizing the femtocell radiated power in an approach similar to [6], where each femtocell sets its power to a value that on aver- age is equal to the received signal strength from the closest macrocell in a target femtocell radius. Another solution to mitigate the interference problem is the use of sector antennas in the FAPs, which has been proposed in [7] to mini- mize the overlapping of coverage areas. Further- more, the use of several radiating elements to perform beamforming and adapting the coverage area of the femtocell to the shape of the house- hold have also been suggested in [24] . Moreover, orthogonal frequency-division multiple access (OFDMA) femtocells have the advantage of allowing the allocation of orthogo- nal frequency/time resources to users. Thus, interference avoidance can be handled through not only power or antenna management, but also subchannel and time slot allocation. 10Access Control MechanismsOpen AccessEvery user can access the FemtocellAdvantages Reduce Interference which is in closed access mechanismOverall throughputTechnical ChallengesSharing Of femtocell resources with nonsubscribersIncrease the number of HandoversMore Chances for Handover failure26/05/151149048. Femtocells. Geysung Choi/ Tanvir Raihan/ Samin Amin Ramay Supervisor A/Prof Sandy K.Sandrasegaran n open access, all users (subscribers and non- subscribers) are allowed to connect. There is thus no distinction between these two groups, and they are just referred to here as users. Technical Challenges and Solutions The use of open FAPs at home would reduce the interference problems caused by CSG FAPs. Indeed, all passing users would be authorized to connect to any femtocell, thus reducing the neg- ative impact of the femtocell tier on the macro- cell network. In this case the users are always connected to the strongest server (either macro or femto), avoiding cross-tier interference. As a result, the overall throughput of the network increases[24]

Nevertheless, open access has some draw- backs as well. It reduces the performance for the femtocell owner due to the sharing of the femto- cell resources with nonsubscribers. Moreover, open access substantially increases the amount of handovers between cells due to the movement of outdoor users. A user moving in a residential area will hand over from one femtocell to anoth- er or to the umbrella macrocell . This will have a negative impact on the operator because the signaling in the network increases as well as the probability of the call being dropped due to failure in the handover process. Furthermore, the chances for handover fail- ure increase if the femtocell neighbor list is not properly configured and updated. Regardless of this, different solutions have been proposed in which a centric sensing of the radio channel is used as a means to obtain parameters about the surrounding environment and update the femto- cell neighbor list

11Access Control MechanismsHybrid access MechanismIntermediate approach between closed and open accessUse Some resources for the Subscribers and some for the nonsubscribers. Technical Challenges Intelligent Management Needed to share resources between the subscribers and nonsubscribers26/05/151249048. Femtocells. Geysung Choi/ Tanvir Raihan/ Samin Amin Ramay Supervisor A/Prof Sandy K.Sandrasegaran Hybrid access methods reach a compromise between the impact on the performance of sub- scribers and the level of access granted to non- subscribers. Therefore, the sharing of femtocell resources between subscribers and nonsub- scribers needs to be finely tuned. Otherwise, subscribers might feel that they are paying for a service that is to be exploited by others. [24] The impact on subscribers must thus be minimized in terms of performance or via economic advan- tages (e.g., reduced costs).

12Access Control MechanismsComparison b/w Closed access & Open access26/05/1513

Table2. Comparison between closed access & open accessVia University of Bedforshire, Access Control mechanism For Femtocells , roche, Valcarce, 200749048. Femtocells. Geysung Choi/ Tanvir Raihan/ Samin Amin Ramay Supervisor A/Prof Sandy K.Sandrasegaran 13Interference ManagementTypes of Interferences

Co-layer: In this case an FAP and a neighbouring Femtocell user belong to the same network layer.

Cross-layer: situations in which an FAP and a macrocell user of interference belong to different network layers. 26/05/151449048. Femtocells. Geysung Choi/ Tanvir Raihan/ Samin Amin Ramay Supervisor A/Prof Sandy K.Sandrasegaran Interference Management

It can be seen that a femtocell not only provides coverage at the customer premises, but also radiates toward neighboring houses as well as outdoors, introducing interference. Due to this and given that femtocells are deployed within the coverage area of existing macrocells, they can cause strong degradation of the macrocells performance. Furthermore, the deployment of new femtocells could also disturb the normal functioning of already existing femtocells. Therefore, in order to reduce the appearance of dead zones within the macrocells and successfully deploy a femtocell network, interference avoidance, randomization, or cancellation techniques must be applied. In the following, it is assumed that the clocks of the femtocells are synchronized with that of the umbrella macrocell. Therefore, and considering that these networks define two separate layers (the femtocell and macrocell layers), interference can be classified as follows [21]:

Cross-layer: This refers to situations in which the aggressor (e.g., an FAP) and the victim (e.g., a macrocell user) of interference belong to different network layers.

Co-layer: In this case the aggressor (e.g., an FAP) and the victim (e.g., a neighboring femtocell user) belong to the same network layer. To overcome the effects of interference, cancellation techniques have been proposed but often disregarded due to errors in the cancellation process [7]. The use of sectorial antennas at the FAP has also been suggested in [8] as a means of reducing interference by decreasing the number of interferers. Similarly, a dynamic selection of predefined antenna patterns has been used in [9] to reduce the power leakage outdoors. However, hardware-based approaches usually imply an increase in FAP cost.

On the other hand, strategies based on interference avoidance also represent efficient alternatives, (e.g., power and subchannel management). Power control algorithms and radio resource management are tools often used in cellular systems to mitigate interference. If they are not applied, users located far from a base station will be jammed by users in much closer positions. These techniques are also necessary in FAPs for the same reasons plus the added problem of cross-layer interference. For example, in closed access femtocells, users located far from the FAP and being asked to raise their power level might produce high levels of interference to neighboring femtocells or even to the macrocell. This is illustrated in the following example. From the point of view of the frequency allocation in OFDMA systems [22].

In UL interference (where an FUE interferes with other FBS) and downlink interference (where an FBS interferes with other FUE).14Co-layer Interference

26/05/1515Figure 7. Co-Tier InterferenceVia http://www.slideshare.net/zahidtg/how-wifi-and-femtocells-complement-one-another-to-optimise-coverage-and-capacity49048. Femtocells. Geysung Choi/ Tanvir Raihan/ Samin Amin Ramay Supervisor A/Prof Sandy K.Sandrasegaran Co tier or Co layer interference are signal received at the femtocell, from other unwanted femtocells. This decreases the quality of communication. Co - tier interfere occur at the same network layer and it mainly between the immediate neighboring femtocell due to low isolation between houses and apartments [23].

However, the signals from other nearby femtocells cause an overall interference higher than the normal femtocell power levels. The carrier to interference and noise Ratio (CINR) value is low; the possibility of establishing communication through any femtocell might not be possible because such location will be a dead zone. Dead zone are area where quality of service are poor and they are created due to asymmetric level of transmission power within the network. This should not be missing up with the concept of coverage holes, when the region is of low pilot CINR due to path loss, the network of the user equipment will fail [23].15Cross-layer Interference

26/05/1516Figure 8. Cross-Tier InterferenceVia http://www.slideshare.net/zahidtg/how-wifi-and-femtocells-complement-one-another-to-optimise-coverage-and-capacity49048. Femtocells. Geysung Choi/ Tanvir Raihan/ Samin Amin Ramay Supervisor A/Prof Sandy K.Sandrasegaran Similarly in cross-tier, UL interference (where FUE close by to the MBS interfere with it other than MUE) and DL interference (where an MBS close by to the FUE interferes with it other than FBS) in Cross-tier interferencesuch as shown above the figure.

Interference in cross tier occurs between different network elements. For example, the unwanted signals by FAP cause interference to downlink of macrocell users and likewise the unwanted signal by macrocell user at the uplink cause interference to FAP user. This is cross tier interference to both network systems. The cross tier interference is more sever in CDMA co- channel deployment due to the reason that both femtocell and macrocell make use the same frequency band. The figure below illustrate cross tier interference. Where the direction of arrows indicate the interference in the network. [23]. 16Mobility Management & Handover Hand-in handover: from a serving MBS to a target FAP

Hand-out handover: from a serving FAP to a target MBS

Inter-FAP handover: from a FAP to another FAP26/05/151749048. Femtocells. Geysung Choi/ Tanvir Raihan/ Samin Amin Ramay Supervisor A/Prof Sandy K.Sandrasegaran In macrocell networks, cell handoffs are triggered when users enter the coverage area of other cells. However, given the coverage size of open/hybrid access femtocells, this occurs more often than in the macrocell case, hence increasing network signaling. Different handoff management procedures are thus needed to allow nonsubscribers to camp for longer periods on nearby femtocells. Furthermore, a hierarchical cell structure (HCS) can also be used to distinguish between macro- and femtocells. In this way, the signaling across layers can be minimized as well as the neighboring cell list that users scan when performing a handoff [23].

Since voice communication has some real time requirements, femtocell provides a reliable hard handover so that the network transmission is seamless to the user.

Femtocell - femtocellFemtocell - 2GFemtocell - 3GIn the transition process from femtocell to macrocell, the mobile station selects the appropriate handover candidate, acquires authentication and connects to the new access point. Recent handsets are configured to switch automatically to 3G because of the high traffic capacity but fall back to 2G by default when coverage is limited. The transition process from macrocell to femtocell is more complex as the mobile station may have to choose between two or multiple neighboring femtocells. The node B coordinates the handover by provisioning the base station a list of allowed access points. The process includes several phases such as preparation, signal measurements, authentication, processing and execution. Figure 5 shows the successive steps between the mobile station, the node B, the access point and the RNC to achieve a handover [19].17Mobility Management & Handover

26/05/1518Figure 9. Handover procedureVia http://www.cse.wustl.edu/~davidh/Pages/femtocell.html#Section2.2

49048. Femtocells. Geysung Choi/ Tanvir Raihan/ Samin Amin Ramay Supervisor A/Prof Sandy K.Sandrasegaran When a mobile device in a WiFi network moves to the outer edge of its Received Signal Strength (RSS) limit it needs to perform a handover of connection from one access point to another. The major concern for femtocell handover is that the coverage area of an individual femtocell is very small. For this reason, it becomes essential that there is a seamless handover to and from femtocells so the user can maintain continuous signal connectivity. There are generally three types of handovers for both WiFi and Femtocells. The first is a simple base station to base station handover where a user moves from the range of one base station to another. The second occurs between base stations and Femto Access Points (FAPs). The base station to FAP handover happens when the mobile user moves from an outdoor area to an indoor area. When the user starts outdoors it sends a request to a cellular base station and when the user then moves indoors the FAP will accept the request and pick up the signal [21].

For this to work there has to be synchronization between the FAP and the cellular base station. The final handover scenario is where the user moves from one FAP to another. This generally happens when there are multiple FAPs in the same vicinity, in an office building for example. The challenge associated with handovers for femtocells is that they are not usually connected to a network environment where mobility is addressed, (again 13 as in an office building where mobility outside the building isnt a concern). Due to the fact that the femtocell must be associated with an IP address, whe a user is mobile the IP addresses would have to change [23]. 18Solutions for handover Improvement of conventional techniques

Power control approach 26/05/151949048. Femtocells. Geysung Choi/ Tanvir Raihan/ Samin Amin Ramay Supervisor A/Prof Sandy K.Sandrasegaran

In general power control is adopted for at least one of the following reasons: first is to mitigate the interference in order to increase capacity of the network to conserve energy in order to prolong battery live, and sencond one is to adapt to channel variations in order to support Quality of Service (QoS) [8]. Power control algorithms are advantageous in that the macro-eNB (MeNB) and HeNB can use the entire bandwidth with interference coordination. The dynamic power setting can be performed either in a proactive or interactive manner each of which again can be performed either in open loop power setting (OLPS) mode, where the HeNB adjust its transmission power based on its measurement results or a predefined system parameters, or closed loop power setting (CLPS) mode in which the power adjustment is done by the HeNB based on the coordination with MeNB [16]. 19Comparison of Femtocells & Wi-Fi

26/05/1520Figure 10. Comparison of Femtocells & Wi-FiVia http://www.slideshare.net/zahidtg/how-wifi-and-femtocells-complement-one-another-to-optimise-coverage-and-capacity49048. Femtocells. Geysung Choi/ Tanvir Raihan/ Samin Amin Ramay Supervisor A/Prof Sandy K.Sandrasegaran There are several difference between Femtocells and Wi-Fi technology

Firstly, they use different frequency band (i.e. 2.4GHz and 5GHz for Wi-fi and from 700MHz to 2.3 GHz for Femtocells in order to communicate with 2G and 3G mobile users)Secondly, Wi-Fi can support more higher system bandwidth to carry data.Third, this is most big different aspect between Femtocells and Wi-Fi, it is data rate. Wi-Fi can provide data rate speed up to 7Gbps (IEEE 802.11ac), however, Femtocells can only provide up to 1 Gbps with LTE-A and WiMAX standard.Finally, communication range is difference.20Comparison of Femtocells & Wi-Fi

26/05/1521Figure 11. Comparison of Femtocells & Wi-FiVia http://www.slideshare.net/zahidtg/how-wifi-and-femtocells-complement-one-another-to-optimise-coverage-and-capacity49048. Femtocells. Geysung Choi/ Tanvir Raihan/ Samin Amin Ramay Supervisor A/Prof Sandy K.Sandrasegaran Femtocells vs. Wi-Fi Coverage & Capacity

Licensed band.

Un licensed band. Must re-use operators available spectrum Operator need not concern with spectrum Spectrum Availability allocation. Therefore mainly used for coverage related issues as with femtocells extension (as well as capacity improvement) Up to 10-30 m (transmit power of 1mW to 100 Up to 100m (transmit power of up to 1W)Coverage mW). Power levels of most Wi-Fi APs are higher Indoor Coverage Power level will depend on the macro network than femtocells. to avoid/mitigate interference. Co-channel interference with macrocell. interference cancellation features in Wi-Fi Interference avoidance and management (Cognitive Radio)(though interference from Interference Issues techniques (Self Organized Networks - SON) non Wi-Fi unlicensed band devices can be a will be necessary . problem) Operator effort is needed for careful frequency No special effort needed on network Network Planning planning and interference avoidance, which is planning also complicated by mobility of femtocells WCDMA 384 kbps, HSDPA 14.4 Mbps (DL) Up to 450 Mbps (IEEE 802.11n) LTE 100 Mbps (DL, 2X2 MIMO) Up to 7 Gbps (IEEE 802.11ac) Data Rates WiBro (802.16) 50 Mbps (DL, 2X2 MIMO) Possibility to provide LTE like data servicesCapacIty LTE-A & WIMAX 802.16m up to 1 Gbps in a 3G environment Data off loading is inherently supported, Data off loading is not inherently making it possible to uniform data plan supported. However 3GPP is currently throughout the network standardizing aspects such mobility Data Offloading management, policy control and charging seamless interworking with mobile networks [18].

21Comparison of Femtocells & Wi-Fi

26/05/1522Figure 12. Comparison of Femtocells & Wi-FiVia http://www.slideshare.net/zahidtg/how-wifi-and-femtocells-complement-one-another-to-optimise-coverage-and-capacity49048. Femtocells. Geysung Choi/ Tanvir Raihan/ Samin Amin Ramay Supervisor A/Prof Sandy K.Sandrasegaran Femtocells vs. Wi-Fi Other Considerations Key Aspect Femtocells Wi-Fi

Seamless communication

Needs a user triggered mechanism. Use the same technology as macro cells. Easy Communication Handoff support for hierarchical handoff. Aspects of seamless mobility (PS) are currently being standardized Seamless Operator may not have control over QoS Quality of Service As the license band is managed by the unless the Wi-Fi network is managed by (QoS) operator QoS is carefully managed the operator Device needs to have Wi-Fi (which most Device Support no special considerations on the device smart phones) [18].

Deployment Aspects

There is a possibility of partnering with Total Cost of third parties for Wi-Fi access.

Deployed by the operator. And may be paid Ownership Wi-Fi deployments improve operator reach for by the consumer. [19]22QUESTIONS ? 26/05/152349048. Femtocells. Geysung Choi/ Tanvir Raihan/ Samin Amin Ramay Supervisor A/Prof Sandy K.Sandrasegaran 23References[1] Femto Forum, "Interference Management In UMTS Femtocells," Http://Www.Femtoforum.Org/Femto/Files/File/FF-UMTS-Interference-Management.Pdf[2] V. Chandrasekhar, J. G. Andrews And A. Gatherer "Femtocell Networks: A Survey",IEEE Commun. Mag.,Vol. 46,Pp.59 -67 2008[3] G.E.M. Zhioua, P. Godlewski, S. Hamouda, S. Tabbane, "Quietest Channel Selection For Femtocells In OFDMA Networks", To Be Published In The Proceecdings Of Mobiwac'10, October 2010.[4]H. Claussen, L. T. W. Ho, And L. G. Samuel, An Overview Of The Femtocell Concept, Bell Labs Technical Journal, Vol. 13, No. 1, Pp. 221245, May 2008.[5] V. Ramaswamy And D. Das, Multi-Carrier Macrocell Femtocell Deployment-A Reverse Link Capacity Analysis, In Proc. IEEE Vehic. Tech. Conf., Sep. 2009, Pp. 16[6] Jeffrey G. Andrews, H Claussen, M Dohler, S Rangan, Mark C. Reed Femtocells: Past, Present, And Future In IEEE Journal On Selected Areas In Communications, Vol. 30, No. 3, April 2012[7] K. L. Yeung And S. Nanda "Channel Management In Microcell/Macrocell Cellular Radio Systems", IEEE Trans. Vehic. Tech., Vol. 45, No. 4, Pp.601 -612 2006[8] S. Ortiz, "The Wireless Industry Begins To Embrace Femtocells", IEEE Computer Society,Vol.41, Issue 7, July 2008, Pp. 14 17 [9] G. D. L. Roche, A. Valcarce, D. Lopez-Perez, And J. Zhang, Access Control Mechanisms For Femtocells, IEEE Communication. Mag., Vol. 48, No. 1, Pp. 3339, Jan. 2010.[10] M. Yavuz et al., 2009, Interference Management and Performance Analysis of UMTS/HSPA+ Femtocells, IEEE Communications Magazine. [11] V. Chandrasekhar, J. G. Andrews, and A. Gatherer, 2008, Femtocell networks: a survey, IEEE Communications Magazine, vol. 46, no. 9, pp. 5967.[12] Simeone, O., Erkip, E. and Shamai Shitz, S. 2009, Robust Transmission and Interference Management For Femtocells with Unreliable Network Access, IEEE Journal on Selected Areas in Communications, vol. 28, no. 9.26/05/152449048. Femtocells. Geysung Choi/ Tanvir Raihan/ Samin Amin Ramay Supervisor A/Prof Sandy K.Sandrasegaran 24References (Contd.)[13] Park, S., and Seo, W. 2010, Beam Subset Selection Strategy for Interference Reduction in Two-Tier Femtocell Networks, IEEE Transactions on Wireless Communications, vol. 9, no. 11.[14] Shu-ping, Y., Talwar S., Seong-choon, L. and Heechang K. 2008, WiMAX femtocells: a perspective on network architecture, capacity and coverage, IEEE Communications Magazine, vol 46, no 10, pp. 58 65.[15] Schiller, J. 2009, Mobile Communications, 2nd Edition, pp.93-164, ISBN 0-321-12381-6.[16] Hasan, S.F., Siddique, N.H., and Chakraborty, S. 2009, Femtocell vs. WiFi A survey and comparison of architecture and performance, 1st International Conference on Wireless Communication, Vehicular Technology, Information Theory and Aerospace & Electronic Systems Technology, pp.916 920.[17] Edwards, C. 2008, The future is femto, IET journal, Volume: 3, Issue: 15, pp. 70 73.[18] Holma H. and Toskala A. 2002, WCDMA for UMTS, John Wiley & Sons, ISBN 978-0470844670.[19] Chowdhury M.Z., Ryu W., Rhee E., and Jang Y. M. 2009, Handover between femtocell and macrocell for UMTS-based networks, 11th International Conference on Advanced Communication Technology, 2009, vol. 1, pp. 237-241.[20] Han K., Choi Y., Kim D., Na M., Choi S., and Han K., 2009, Optimization of femtocell network configuration under interference constraints, 7th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks, pp. 1-7.[21] Arjona, A., and Verkasalo, H. 2007, Unlicensed Mobile Access Handover and Packet Data Performance Analysis, Second International Conference on Digital telecommunications, 2007. ICDT 07, pp.9-19.[22] Giupponi, L., and Ibars, C, Distributed interference control in OFDMA-based femtocells, in IEEE PIMRC10, Sept. 2010, pp. 12011206.[23] Zhou, H., Hu, D., Mao, S., Agrawal, P., and Reddy, S. A, Cell association and handover management in femtocell networks, inProc. IEEE WCNC2013, Shanghai, China, Apr. 2013, pp.1-6.[24] Roche, Valcarce, Access Control mechanism For Femtocells ,in University of Bedforshire 2007.

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