Business models for deployment and operation of femtocell networks; - Are new cooperation strategies needed for mobile operators?

In this paper we discuss different business models for deployment and operation of femtocell networks intended for provisioning of public mobile broad band access services. In these types of business cases the operators use femtocells in order to reduce investments in "more costly" macro networks since the traffic can be "offloaded" to "less costly" femtocell networks. This is in contrast to the many business cases presented in Femtoforum where femtocells mainly are discussed as a solution to improve indoor coverage for voice services in homes and small offices, usually for closed user groups The main question discussed in this paper is if "operators need to consider new forms of cooperation strategies in order to enable large scale deployment of femtocells for public access?" By looking into existing solutions for indoor wireless access services we claim that the answer is both "Yes" and "No". No, since many types of cooperation are already in place for indoor deployment. Yes, because mobile operators need to re-think the femtocell specific business models, from approaches based on singe operator networks to different forms of cooperation involving multi-operator solutions, e.g. roaming and network sharing. --

Adaptive Power Control Applying to Femtocell

Femtocells are expected to increase network capacity, extend macrocell coverage, and introduce new services. Because Femtocells share the same frequency band with macrocells in many cases, the femtocell base station (BS) must mitigate the interference with macrocells as well as ensure coverage in customer premises. However, conventional femtocell BS transmit power setting have not adequately accounted for the interference with neighbouring macrocell mobile stations (MSs), leading to small femtocell user throughout. In the paper, we describe an adaptive power level setting scheme i.e. Distributed Power Control algorithm to mitigate the interference of MSs in the basis of the received power levels. In DPC, each pair of transmitter (e.g., an MS) and receiver (e.g., the BS) does not need to know the transmit power or channel quality of any other pair. At each time slot, all it needs to know is the actual SIR it currently achieves at the receiver. Then, by taking the ratio between the fixed, target SIR and the variable, actual SIR value measured for this time slot and multiplying the current transmit power by that ratio, we get the transmit power for the next time slot. This update happens simultaneously at each pair of transmitter and receiver. This is how DPC provides adaptive nature to Femtocell

A New Handover Strategy between Femtocell and Macrocell for LTE-based Network

[[abstract]]The femtocell networks that use Home eNodeB (HeNB) and existing networks as backhaul connectivity can fulfill the upcoming demand of high data rate for wireless communication system as well as can extend the coverage area. We consider so me parameters which are interference, velocity, RSS and QoS level in handover. We propose a new handover strategy between femtocell and macrocell for LTE-based network in hybrid access mode. This strategy can avoid unnecessary handover and reduce handover failure. In this paper we analyzed three scenarios after handover decision strategy procedure: hand-in (CSG and non-CSG), hand-out.[[notice]]補正完畢[[conferencetype]]國際[[conferencedate]]20110703~20110704[[iscallforpapers]]Y[[conferencelocation]]Sao Paulo, Brazil[[countrycodes]]BR

Analysis of femtocell for better reliability and high throughput

Abstract: An unrelenting need for mobile broadband data has become the norm for end users. Mobile operators are now faced with a challenge to deliver higher data rates thus has prompted developments for new innovations in mobile technology to satisfy this data hungry generation. Poor indoor building penetration have been a major stumbling block in achieving higher data rates as good signal strength of better quality influences higher data rates. Methods to solve indoor penetration problems such as cranking up power on existing base stations can be an alternate but this can potentially introduce high interference to the system and effectively decrease system capacity. Like in any other wireless communication environment, having a transmitter and receiver closer to each other will potentially increase signal strength thus effectively increasing signal quality and potentially higher data rates. This inevitably means more base stations need to be installed to improve coverage. This idea is not feasible ! in practice based on financial constraints using traditional macro and micro sites thus the emergence of FemtoCell seems to be a feasible endeavour. A FemtoCell BS is a self-installed low powered base station connected to the mobile operator via backhaul using IP connection. This device brings a lot of benefits such as Opex savings, increased spectral efficiency, improved battery life and higher data rates for customers resulting from increased signal Strength. In this paper an overview of advancement of cellular networks from legacy standards 2G to 4G-LTE/LTE-A and benefits/challenges of FemtoCell are analysed

Business Innovation Strategies to Reduce the Revenue Gap for Wireless Broadband Services

Mobile broadband is increasing rapidly both when it comes to traffic and number of subscriptions. The swift growth of the demand will require substantial capacity expansions. Operators are challenged by the fact that revenues from mobile broadband are limited, just a few per cent of APRU, and thus not compensating for declining voice revenues, creating a so called "revenue gap". Concurrently, mobile broadband dominates the traffic, set to grow strongly. In this paper we analyze the potential of different strategies for operators to reduce or bridge the revenue gap. The main options are to reduce network costs, to increase access prices and to exploit new revenue streams. The focus in the paper is on cost & capacity challenges and solutions in the network domain. Operators can cooperate and share sites and spectrum, which could be combined with off-loading heavy traffic to less costly local networks. In the network analysis we illustrate the cost impacts of different levels of demand, re-use of existing base station sites, sharing of base stations and spectrum and deployment of a denser network. A sensitivity analysis illustrates the impact on total revenues if access prices are increased, whether new types of services generate additional revenues, and if it fills the revenue gap. Our conclusion is that the different technical options to reduce the revenue gap can be linked to business strategies that include cooperation with both other operators as well as with non-telecom actors. Hence, innovations in the business domain enable technical solutions to be better or fully exploited.Wireless Internet access, data traffic, revenues, network costs, spectrum, deployment strategies, HSPA, LTE, operator cooperation, value added services, NFC, B2B2C.

Radio network management in cognitive LTE-Femtocell Systems

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University London.There is a strong uptake of femtocell deployment as small cell application platforms in the upcoming LTE networks. In such two-tier networks of LTEfemtocell base stations, a large portion of the assigned spectrum is used sporadically leading to underutilisation of valuable frequency resources. Novel spectrum access techniques are necessary to solve these current spectrum inefficiency problems. Therefore, spectrum management solutions should have the features to improve spectrum access in both temporal and spatial manner. Cognitive Radio (CR) with the Dynamic Spectrum Access (DSA) is considered to be the key technology in this research in order to increase the spectrum efficiency. This is an effective solution to allow a group of Secondary Users (SUs) to share the radio spectrum initially allocated to the Primary User (PUs) at no interference. The core aim of this thesis is to develop new cognitive LTE-femtocell systems that offer a 4G vision, to facilitate the radio network management in order to increase the network capacity and further improve spectrum access probabilities. In this thesis, a new spectrum management model for cognitive radio networks is considered to enable a seamless integration of multi-access technology with existing networks. This involves the design of efficient resource allocation algorithms that are able to respond to the rapid changes in the dynamic wireless environment and primary users activities. Throughout this thesis a variety of network upgraded functions are developed using application simulation scenarios. Therefore, the proposed algorithms, mechanisms, methods, and system models are not restricted in the considered networks, but rather have a wider applicability to be used in other technologies. This thesis mainly investigates three aspects of research issues relating to the efficient management of cognitive networks: First, novel spectrum resource management modules are proposed to maximise the spectrum access by rapidly detecting the available transmission opportunities. Secondly, a developed pilot power controlling algorithm is introduced to minimise the power consumption by considering mobile position and application requirements. Also, there is investigation on the impact of deploying different numbers of femtocell base stations in LTE domain to identify the optimum cell size for future networks. Finally, a novel call admission control mechanism for mobility management is proposed to support seamless handover between LTE and femtocell domains. This is performed by assigning high speed mobile users to the LTE system to avoid unnecessary handovers. The proposed solutions were examined by simulation and numerical analysis to show the strength of cognitive femtocell deployment for the required applications. The results show that the new system design based on cognitive radio configuration enable an efficient resource management in terms of spectrum allocation, adaptive pilot power control, and mobile handover. The proposed framework and algorithms offer a novel spectrum management for self organised LTE-femtocell architecture. Eventually, this research shows that certain architectures fulfilling spectrum management requirements are implementable in practice and display good performance in dynamic wireless environments which recommends the consideration of CR systems in LTE and femtocell networks

An energy-centric handover decision algorithm for the integrated LTE macrocell–femtocell network

Femtocells are attracting a fast increasing interest nowadays, as a promising solution to improve indoor coverage and system capacity. Due to the short transmit-receive distance, femtocells can greatly lower transmit power, prolong handset battery life, and enhance the user-perceived Quality of Service (QoS). On the other hand, technical challenges still remain, mainly including interference mitigation, security and mobility management, intercepting wide deployment and adoption by both mobile operators and end users. This paper introduces a novel energy-centric handover decision policy and its accompanied algorithm, towards minimizing the power consumption at the mobile terminal side in the integrated LTE macrocell–femtocell network. The proposed policy is shown to extend the widely-adopted strongest cell policy, by suitably adapting the handover hysteresis margin in accordance with standardized LTE measurements on the tagged user’s neighbor cells. Performance evaluation results show that significantly lower interference and power consumption can be attained for the cost of a moderately increased number of network-wide handover executions events

A survey of machine learning techniques applied to self organizing cellular networks

In this paper, a survey of the literature of the past fifteen years involving Machine Learning (ML) algorithms applied to self organizing cellular networks is performed. In order for future networks to overcome the current limitations and address the issues of current cellular systems, it is clear that more intelligence needs to be deployed, so that a fully autonomous and flexible network can be enabled. This paper focuses on the learning perspective of Self Organizing Networks (SON) solutions and provides, not only an overview of the most common ML techniques encountered in cellular networks, but also manages to classify each paper in terms of its learning solution, while also giving some examples. The authors also classify each paper in terms of its self-organizing use-case and discuss how each proposed solution performed. In addition, a comparison between the most commonly found ML algorithms in terms of certain SON metrics is performed and general guidelines on when to choose each ML algorithm for each SON function are proposed. Lastly, this work also provides future research directions and new paradigms that the use of more robust and intelligent algorithms, together with data gathered by operators, can bring to the cellular networks domain and fully enable the concept of SON in the near future