Telektronikk 1.2010

Guest Editorial - Mobile Broadband

Mobile and wireless communications technologies have undergone a huge development since the first automatic cellular networks were introduced in the 1980s. The technological development has been exciting, and we see the latest step on this ladder with the introduction of the LTE – Long Term Evolution systems. This article is a walk-through, mostly of the technological development since data services became available also via mobile and wireless systems, but we also present some facts about the explosive market growth and how this growth is forecast to continue the coming years.

This article concerns the roles that human issues and psychology play in technical development. An ‘MBB (Mobile Broadband) staircase’ model helps reveal different stages where users may have problems using MBB. It is emphasised that the users who are particularly unable to have their needs met with MBB are those that struggle with technology in general. Difficulties with MBB do not hit ‘technology achievers’ as hard, as they can usually make it work after some effort. However, a lot of what may be learned from studying ‘technology strugglers’ can benefit the ‘technology achievers’ also. Indeed, it is argued that all people, regardless of their aptitude with technology, are faced with problems at some levels of the ‘MBB staircase’. This is because new technologies must adapt to the ‘old brains’ of users, because human evolution has not prepared us for using telecommunication services such as MBB. It is possible to improve MBB by better understanding the behaviour and needs of users. By including a psychological perspective this article emphasises that users have both conscious and unconscious behaviours which need to be taken into account. We address elements concerned with usability (such as the user interface), technical parameters that need to be optimised (such as end-to-end delay) and how this can really be a help for those that are developing the services and technology for users.

When entering the second decade of the new millennium mobile communications experiences several shifts. Up to this date, mobile communications have been synonymous with mobile telephony. Not so anymore. Already now, the market appreciation of powerful data services combined with the ambition ‘working or playing anywhere anytime’ is conspicuous. This coincides with extending the IP protocol all the way to the mobile terminal, thereby putting mobile VoIP on the agenda. The demand for capacity both over the radio interface and backhaul network will be of quite another magnitude than before. The technology shift comes during the liberalisation of spectrum management, including free first-hand market, free second-hand market and technology neutrality. Demand for more spectrum will be imminent and so will demand for spectrum at different levels of the radio frequency spectrum, at least the opportunity to combine spectrum both below and above 1.5 GHz. This article takes the reader through the major challenges emerging in this demanding landscape and suggests where the spectrum wells for mobile broadband will be found in the next decade.

In this paper we take a deep dive into the two major mobile broadband radio standards developed by the 3rd Generation Partnership Project, namely High Speed Packet Access (HSPA) and Long Term Evolution (LTE). An overview of the two systems is given, and we identify the main differences, ie. the multiple access technique, the architecture and the size of the operation bandwidth. The performance is also investigated, and it is shown that the newer LTE system has an evolutionary performance gain over HSPA. Looking at deployment possibilities, the 2.1 GHz band is the main capacity band for HSPA, while the 900 MHz band will probably be the main coverage band. For LTE, it seems that the corresponding bands will be 2.6 GHz for capacity and the digital dividend (ie. 800 MHz in Europe) for coverage. It should be noted that utilizing the same band for several technologies, as will be the case for 900 MHz in a transition period, introduces some co-existence challenges that must be dealt with.

The new cellular system from the 3GPP is commonly referred to as ‘LTE’ or ‘4G’. The system comprises a radio part, called evolved UTRAN (eUTRAN) and a core network part called the Evolved Packet Core. Together these constitute what is called the Evolved Packet System. In addition to supporting eUTRAN, the new all-IP core network includes a large number of new features and enhancements compared to the legacy mobile core networks. The new core network supports GERAN and UTRAN radio accesses and supports interworking with the legacy circuit switched domain. Non-3GPP networks, like Wireless LAN, are also supported, enabling the operator to offload the mobile macro network. Included in the new architecture is also the new policy- and QoS regime, opening for new services and being required to support voice calls in this new all-IP system.

WiMAX is a fixed and mobile wireless access technology based on the IEEE 802.16 standard. It is a technology that has its origin in the computer industry and is an alternative to 3GPP technologies like HSPA and LTE. This article seeks to give a tutorial overview of the WiMAX technology, its current status and future development.

Femtocells have been a hot topic since 2007, but femtocells are still struggling to get market acceptance. So far we have seen 12 launches including trials, and there is still a large uncertainty of the future footprint of femtocells. Toward the users the promises of femtocells are first and foremost better indoor coverage and capacity, as well as specific femtozone services like notifications when the children enter or leave the home. The femtocell is also a means for connecting the mobile phone smoothly to the connected home network. For the operator femtocells can be a platform for maximising revenue and margin through significantly lower delivery costs, as well as the possibility of increasing network capacity without the need for further investments in macro network upgrades. Offloading of the macro network has became an extremely hot topic amongst operators experiencing capacity problems in the mobile broadband network due to extensive use of smart phones and large screen terminals (PCs) connected through the mobile broadband networks. It is imperative for the mobile broadband operators to handle the ever increasing capacity needs in a cost effective way to keep the business sustainable. Femtocells is a solution to meet the operator community’s urgent need for handling the rapid increase in mobile broadband usage that challenges the operators’ profitability. We know quite well the technical performance and roadmaps of femtocells, whereas there is a larger uncertainty with respect to the market acceptance of femtocells. Even though several launches have been announced, the real proof of the concept is the market uptake and user approval of the femtocells technology. Sprint in the US launched 2G femtocells supporting the CDMA 1xRTT standard in 2007 and is about to update the service to support the 3G CDMA EV-DO standard. The most recent launches are Vodafone UK’s launch of the 3G UMTS/HSPA femtocell service named ‘Sure Signal’, as well as AT&T’s femtocell launch in the US. Reports indicate a rapid growth in the uptake of femtocells in the UK, whereas the launch at AT&T is too recent to give any figures.

In this article we shall take a brief look at access security in the 3GPP-based mobile broadband systems. We shall mainly look at access security in UMTS and LTE, but will also briefly look at the latest status of GERAN access security. Furthermore, we shall see that the GSM SIM is not an acceptable platform for supporting true mobile broadband subscribers.

Today, most of the prime radio frequencies are exclusively assigned for a number of years making it difficult to get access to new spectrum. Yet, measurements have repeatedly shown that at any location at any time a large portion of the spectrum is actually not used. From a regulatory and political point of view the underutilization of spectrum is hardly acceptable. Politicians argue for more competition and better telecommunication services for the public. Users want a lower threshold to broadband access, regardless of location. Conversely, operators’ networks suffer capacity limitations at times, particularly for an increasingly demanding mobile broadband offer, including indoor usage. Interest in more flexible, reconfigurable radio systems is fuelled by the rapidly growing demand for data traffic. One of the means to achieve a more efficient utilization of spectrum and therefore decreasing the cost per delivered bit is Cognitive Radio (CR), which relies on the opportunistic use of frequency voids. A number of regulatory bodies are promoting a more liberalized use of spectrum that would also encompass a more dynamic usage. This trend is also reflected in several standardisation forums that develop methods enabling a more flexible and highly dynamic spectrum usage. The roadmap for CR and particularly how it will be brought to the market is difficult to assert, but large international efforts are under way to achieve a first consensus in the World Radio Conference in 2012. Regulatory questions include licensing regimes, enforcement of the regulations and agreement possibilities between actors, to name a few. This will give a frame for CR and the very role of actors and regulatory bodies could be reshaped in the process. Two European research projects, SENDORA and QoSMOS, have supported the study of how to implement such CR systems, what would the different actors gain as well as the potential threats. Possibilities for cost optimization but also new opportunities such as micro-trading of spectral resources between different actors have emerged. These projects have allowed shaping an early operator’s strategy on CR that can be promoted in a number of different bodies, particularly the spectrum regulatory authorities.

Up until recently, very little consideration has been given to reducing the energy consumption of the networks supporting mobile communication. This has now become an important issue since with the predicted boost in traffic, network operators are required to upgrade and extend their networks, increasing also their overall energy consumption. However, traffic analysis shows that during a 24-hour period, the volume of carried traffic varies continuously, with the network operating anywhere close to its full capacity for very short periods of time. The problem is that during hours of low network traffic the energy consumption remains high. This article proposes two major solutions for mitigating this problem. In the first case, an energy saving between 14% and 36% is observed by allowing the network to dynamically optimize its available capacity based on the traffic being carried. In the second case, energy saving is obtained by reducing the amount of required network upgrades. This is done by accommodating increasing traffic during less busy hours to provide an adequate incentive for subscribers to spread some of their daily traffic. Over a period of five years, besides saving on the investments, an indirect energy saving of 30% is possible. In all investigations, the network performance is given priority and always maintained.

Mobile network traffic shows a dramatic growth, particularly due to new broadband services. The backhaul is becoming increasingly important in providing competitive broadband mobile services. Microwave links is one of the most common backhaul technologies for mobile network base stations. The transition from basic voice services to mobile broadband services now taking place in all markets will require significantly higher backhaul capacity, and traditional 2 Mbit/s or a few Mbit/s lines are not sufficient. One option is the recently developed single carrier gigabit radio links, particularly for the network sections close to the base station site. These radio systems operate in the millimetre bands, ie. 60-90 GHz and are characterised by offering 1 Gbit/s capacity in a single radio channel while being developed towards even higher bitrates. The possible range for such systems is a few kilometres depending on the local climate.

This paper shows the first results from ongoing research collaboration between Nokia Siemens Networks, Aalborg University, and Telenor Denmark, with the target of investigating mobile broadband network evolution towards 2015. In recent years there has been a boom in mobile data traffic growth, which has been enabled by HSPA launch, flat-rate tariff, and a wide availability of USB radio modems and smart phones. Recent measurements in the Telenor Denmark network have shown a growth of more than 300% yearly, and we forecast that the traffic volume will increase exponentially with an average annual increase of 70% until 2015, ie. a total traffic increase factor of 20-25 from 2009 to 2015. We analyse two network evolution options which both fulfil the capacity and coverage requirements. First the upgrade of the existing macro sites is considered with optimization of antenna tilting, triple carrier support, HSPA+ and 6 sectors enhancements. For the second option, the 3rd carrier is used for a micro cell deployment instead of an additional macro cell carrier. An economic evaluation of both network evolution options by means of Total Cost of Ownership (TCO) is performed. Both upgrade options meet the performance requirements and are almost equal with regard to the TCO. The analysis also indicates that LTE technology in new spectrum is required in the near future.

Business case modelling shows that the Mobile Broadband (MBB) business in the Hungarian market for the market player Pannon has a payback time of seven – eight years and the NPV (Net Present Value) is positive after nine years, excluding initial 3G licence fee. The profitability curve is more or less on the same level as for the 2G/voice business in Pannon, reflecting the CAPEX intensiveness of the MBB business based on 3G/HSPA. The most important sensitivities for achieving a profitable MBB business are ARPU and customer uptake. Thus, short-term actions should focus on rapid market penetration of MBB access where there is demand with stable price points that ensure product and segment profitability. Further the network costs must be monitored and controlled, both with selected network roll-out & upgrades and traffic management. To reduce risk it is essential to deploy total cost of ownership (TCO) measures to negotiate transparent vendor prices with caps on relevant cost levels to decouple network cost from traffic volume. Looking at the total mobile business the MBB revenue seems to only offset the decrease in the voice/ SMS revenue as this market matures. To ensure revenue growth and profitability for the total mobile business there will be a need to extend the MBB business into personal Internet, probably in a combination of subscriptions across handsets, PCs and other personal devices. This can either be reached by more segmented Internet access offers giving 100% or more population penetration, or by taking a position and get some extra revenue from personal service offering on top of the Internet access.

The Promonte Wireless Broadband (PWB) project has been a collaboration project between Telenor Research & Innovation1) (R&I) and the Telenor-owned operator Promonte in Montenegro. The PWB project’s main goals were to roll out an all-IP network including Fixed WiMAX, Wi-Fi and HSPA using a common core network and to investigate the business potential related to different combinations of these wireless technologies. The project mandate was approved in April 2008 and the project ended October 2009, and currently the PWB network is fully managed and operated by Promonte. This paper summarizes the key experiences from the PWB project and shows up-to-date traffic statistics for the network.

The aim of this paper is to give a summary of the use of electronic identifiers in public e-procurement applications, and to suggest ways in which that use can be standardised to the benefit of all parties concerned. All procurement systems are using identifiers in business documents that are structured according to international standards, but they contain identifiers that have formats and qualities defined within a group, like a national market. The paper suggests an approach to achieve open cross border exchange of electronic procurement documents and its contained identifiers. One key to borderless and open electronic procurement is to design standardised systems for the handling of identifiers and related trustworthy assertions. We examine the relative roles of identifiers and assertions, to identify some of the design criteria which such systems would need to satisfy.

After having coordinated Telenor’s engagement in EU-research for almost two decades, I felt that the time was ripe for a historical review of this important collaborative research from its start in the mid 1980s until early 2010. During this period of 23 years Telenor has participated in about 100 EU projects, of which 96 are mentioned in this report. I try to convey, in broader terms, the reasoning behind Telenor’s engagements as a response to the ever active and dominating role played by the EU Commission, rather than to give extensive descriptions of all our projects. Needless to say, the review is flavored by my own recollection of the events, so are the projects dwelt upon. Our records from the first two framework programs (RACE I & RACE II) are unfortunately incomplete. The material in chapters 2.1 and 2.2 is thus collected from various sources (including my memory), and there is no guarantee that some projects may not have slipped through. As the title indicates, the focus of this report is on EU projects. However, both Eureka and Eurescom, as means for collaborative research in Europe, deserve to be mentioned. This is done in chapters 3 and 4 respectively. Both Eureka, being industry driven, and Eurescom, being Telco owned, offered projects that in many ways complemented the ones from EU. This is still the case for Eureka, whereas Eurescom today only invites for Studies, ie. small projects of about three months’ duration.

A list of acronyms and terms used in this issue.