Jan Markendahl

A comparative study of deployment options, capacity and cost structure for macrocellular and femtocell networks

In this paper we will compare the cost & capacity performance of femtocell and macrocellular networks. The motivation is the possibility to use femtocells as complement or as replacement of wide area networks and hence to save investments in macrocell networks. In this study the femtocells thus are used as a tool for operators to reduce network costs for mobile broadband. This represents another business case than the often presented cases with focus on improved indoor coverage in homes with focus on voice services. Our techno-economic analysis is made as a comparative case study where capacity and cost is analyzed for wireless broadband deployed in a newly built office area with high user density. In addition to wall penetration losses we take into account; the level of user demand, the density of existing macro base station sites, the recent improvements in cost and spectral efficiency for radio access technologies, and the use of wider system bandwidths. The main finding of the study is that femtocell solutions, for the considered demand levels, are more cost efficient when new macro base station sites need to be deployed, otherwise macrocell solutions are more cost-efficient.

Business models and resource management for shared wireless networks

In this paper we analyze main use cases for sharing wireless access networks between multiple operators and service providers. Network sharing has been proposed as a method to lower roll-out costs for 3G operators in Europe, and is widely used in WLAN systems where local access providers offer wireless access to service providers. A similar structure also exists in cellular networks where mobile virtual network operators (MVNO) provide mobile services without having a mobile network of their own. The development points at a further fragmentation of wireless access networks into specialized service providers that connect to local service and access providers, possibly via an inter-connection provider serving with core network functionality. In this context, we propose a framework for how radio resources could be managed using service level agreements (SLA) and analyze key differences between the SLA for different types of service and network providers.

Device-to-device communications and small cells: enabling spectrum reuse for dense networks

In the evolution of communication networks, there has always been a need to increase the capacity to cope with the continuous growing demand for data transmission. However, with the arrival of the Internet-of-Things and the commoditization of broadband access through smartphones, tablets, smart-watches, and all types of connecting devices, future networks must be capable of providing higher bandwidth and Quality of Experience, as wellas operating in dense networks with a massive number of simultaneous connections. This high number of connections will be very heterogeneous, spanning from highly-demanding data rate applications to low-complexity and high energy-efficient Machine-to-Machine communications. In such a dense and complex scenario, a more flexible use of spectrum resources is deemed to be the way to meet the growing requirements for data transmission. In particular, this article focuses on Device-to-Device communications and small cell deployments as emerging facilitators of such a demanding and heterogeneous scenario. The pros and cons of both complementary strategies are identified from both a technical and a business point of view, and main standardization activities are discussed. The aim of this article is to identify and describe open challenges and to inspire new areas for research that make viable the next generation of dense networks.

Cost drivers and deployment scenarios for future broadband wireless networks - key research problems and directions for research

The most prominent problem in providing anywhere, anytime wideband mobile access is the towering infrastructure cost as it is basically proportional to the bandwidth provided. We provide a simple, initial, analysis of the various infrastructure cost factors. This analysis shows that, contrary to what one may expect, the infrastructure cost is not dominated by electronic equipment, but rather by other deployment related costs (towers, wiring, building, network connections) and maintenance costs. In the paper some novel architectural approaches for future wideband mobile access focusing on these dominant cost factors are described and the related key research issues are discussed.

Analysis of macro — femtocell interference and implications for spectrum allocation

Deployment of femtocells represents a promising solution to increase cost-capacity benefits for network operators and provide higher data rates to end-users. Femtocells are conceived to provide indoor wireless access to a cellular network through a Home Base Station, which is connected via internet to the operators core network, helping to improve coverage in indoors, offload the macrocell and reduce costs for operators. However, large scale deployment of femtocells can severely interfere with the existing macrocell within which they are deployed, particularly when operating in co-channel or in immediate adjacent channels with respect to the macrocell and when using a closed access policy. For instance, macrocell coverage holes in the downlink will appear, i.e. zones in the vicinity of a home base station where interference from home base station signals will prevent macrocell users to receive the desired service from the macrocell network. In this paper, we estimate macrocell coverage holes produced by closed access femtocells when both, macro and femto networks operate FDD WCDMA-based technologies. We investigate the case when the home base station transmits at constant power and when uses a power adjustment mechanism, and for different values of separation in the frequency domain. Results show that coverage holes at the edge of the macrocell can have a radius up to 30 meters when the same carrier is used and up to 5 m when carriers separated 5 MHz are used. Finally, we analyze and discuss how coverage and spectrum allocation are influenced by varying the carrier separation.

Analysis of Business Models and Market Players for Local Wireless Internet Access

Internet access now changes from mainly being a service consumed in own and fixed locations to be a service used at any location. The main topic in this paper is to address what kind of market actor that will be the most important for the provisioning of these public Internet access services. The research questions and methodology are related to business roles, market actors, customer relations, payment options and business mechanisms. The analysis is based on interviews with market actors within and outside the telecom sector that are candidates to take one or several business roles for access provisioning. The main finding of the analysis is that public local access provisioning to a large extent differs from the traditional operator business Actors from outside the telecom sector start to enter telecom business and the main driver is to support the non-telecom core business. The access is often provided based on temporary or short term customer relations.

Decoupling of revenues and traffic - Is there a revenue gap for mobile broadband?

Mobile broadband is increasing rapidly both when it comes to traffic and the number of subscriptions. Operators are challenged by the fact that revenues from mobile broadband are de-coupled from the traffic. In this paper we will analyze if this de-coupling results in a “revenue gap” for the combined voice and mobile broadband business and, if this is the case, how significant the gap is. We analyze a country and operator case where the increasing user demand requires network upgrades. The impact of increasing traffic, revenues and costs is analyzed in terms of profit margin for the voice and mobile broadband businesses. The results show that the overall profit for the modeled operator decreases due to declining voice revenues. The contribution from mobile broadband depends heavily on the amount of traffic growth and prices.

Drivers of Novel Access Provisioning -Re-Use Aspects and Operator Cooperation

New network and business architectures with low cost factors are necessary to promote development of extensive usage of a multitude of high data rate wireless services similar to the Internet. The novel access provisioning (NAP) project investigates the possibilities in local access and service provisioning as a complement to existing mobile networks. We expect that successful high bandwidth mobility services require more than local coverage even if wide area coverage is compromised. Many local access providers need to cooperate to make the service reasonably accessible. Different drivers of new market players and business models are analyzed

On spectrum allocation and interference management for WCDMA and OFDMA femtocells

In this paper we analyze how femtocell base stations (FBS) cause interference in the receivers of user terminals connected to macro base stations. A coverage hole around a FBS appears when closed access strategies are used, i.e. when only authorized users can access the FBS, and when the FBS shares the same or a portion of the macrocell frequency channel. At the cell borders of a macrocell the coverage holes can be large, especially for indoor users (10 – 30 m radius for the investigated cases). The coverage holes can be reduced if different frequency channels are allocated for macrocell and femtocell operation, e.g. down to 1 – 2 m for WCDMA femtocells in adjacent channels. When separation in frequency is not feasible, dynamic channel allocation (OFDMA) or adjustment of the FBS transmission power can be used to reduce the coverage holes. However, the different dynamic strategies have drawbacks in the form of reduced FBS performance and increased system complexity. Operators should consider open access schemes when using co-channel operation.

The M2M promise, what could make it happen?

Machine-to-Machine (M2M) communications is a topic of great importance that maintains an ongoing interest in the academic community and in countless industries and services. Technological advances allow the successful deployment of particular solutions but many potential applications still face limitations that prevent them from happening. This paper compares data collected from five implementation cases in order to analyze key issues related to their value proposition and the challenges that currently limit the adoption of M2M communications.