Jens Zander

Jens Zander
KTH Royal Institute of Technology | KTH · Department of Communication Systems (CoS)

Dr Tech (Ph.D.)

About

222
Publications
29,851
Reads
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8,254
Citations
Additional affiliations
June 1989 - present
April 1979 - January 1985
Linköping University
Position
  • Research Assistant
Education
March 1979 - January 1985
Linköping University
Field of study
  • Electrical Engineering

Publications

Publications (222)
Article
Full-text available
We report results from the recently finished QUASAR project, which has studied overall system aspects of cognitive radio technologies and has paid attention particularly to the economic viability of different use cases. We find that successful secondary sharing goes far beyond the detection of spectrum holes. Large-scale commercial success requires...
Article
Full-text available
Data rates of mobile communications have increased dramatically during the last decade. The industry predicts an exponential increase of data traffic that would correspond to a 1000-fold increase in traffic between 2010 and 2020. These figures are very similar to ones reported during the last Internet boom. In this article we assess the realism of...
Article
Full-text available
Mobile communication networks alone today consume 0.5 percent of the global energy supply. Meeting the rapidly increasing demand for more capacity in wireless broadband access will further increase the energy consumption. Operators are now facing both investing in denser and denser networks as well as increased energy cost. Traditional design parad...
Patent
Embodiments include methods for a network node in a wireless network to manage network resources. Such methods include mapping one or more application-level performance requirements to one or more network performance requirements. The mapping can be based on a Markov chain model and the application-level performance requirements can be associated w...
Article
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In-flight broadband connectivity (IFBC) is a significant open market for mobile network operators considering more than 3.3 billion passengers being served by airlines in 2015. On-board broadband services are provided via air-to-ground (A2G) connectivity through direct A2G communications (DA2GC) and satellite A2G communications (SA2GC). Available o...
Conference Paper
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The Random Access (RA) procedure in cellular networks is not capable of functioning properly during high access load conditions. For this purpose, overload control mechanisms are needed. Most proposed mechanisms in the literature offer a tradeoff between the allowed access rate and experienced delay. However, when the maximal tolerated delay and th...
Article
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Cellular networks are optimized by targeting multiple objectives. Usually, the different objectives are not coherent: minimizing the transmit power; the number of base station (BS) sleep-mode switchings, ie, active/sleep state transitions; and the activity of the BSs and guaranteeing the quality-of-service (QoS) of users. Hence, suitable trade-offs...
Conference Paper
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In addition to the Mobile Broadband (MBB) services , future cellular networks will need to cope with a range of new " Internet of things " (IoT) services. LTE-Advanced and future generation cellular technologies should support both service sets within one network in order to keep the service costs and deployment expenses low. Massive IoT services r...
Article
It has become increasingly clear that the current design paradigm for mobile broadband systems is not a scalable and economically feasible way to solve the expected future 'capacity crunch', in particular in indoor locations with large user densities. 'Moore's law', e.g. state-of-the art signal processing and advanced antenna techniques now being r...
Article
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The forthcoming 5G cellular network is expected to overlay millimeter-wave (mmW) transmissions with the incumbent micro-wave (μW) architecture. The overall mm-μW resource management should therefore harmonize with each other. This paper aims at maximizing the overall downlink (DL) rate with a minimum uplink (UL) rate constraint, and concludes: mmW...
Conference Paper
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What does millimeter-wave (mmW) seek assistance for from micro-wave ({\mu}W) in a mmW overlaid 5G cellular network? This paper raises the question of whether to complement downlink (DL) or uplink (UL) transmissions, and concludes that {\mu}W should aid UL more. Such dedication to UL results from the low mmW UL rate due to high peak-to-average power...
Article
As the energy bill for mobile operators rises with the continuing traffic growth, energy efficiency problems attract an increasing attention in the telecommunication industry. However, the investment for the implementation of any energy-saving solution could be so costly that it may not achieve the total cost reduction. Therefore, the economic viab...
Conference Paper
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This paper proposes a cellular network exploiting millimeter-wave (mmWave) and ultra-densified base stations (BSs) to achieve the far-reaching 5G aim in downlink average rate. The mmWave overlaid network however incurs a pitfall that its ample data rate is only applicable for downlink transmissions due to the implementation difficulty at mobile use...
Article
The need to meet users' expectations in the ‘mobile data avalanche’ represents a significant challenge for mobile network operators. More spectrum is a natural way to meet these requirements in a cost and time-efficient way, but new, exclusively licenced spectrum is increasingly hard to come by. Instead, vertical spectrum sharing has been discussed...
Article
Full-text available
With increasing number of TV channels and growing need for on-demand services, the traditional digital terrestrial television (DTT) is becoming a less attractive way of distributing TV contents. As an alternative, we discuss a converged platform in UHF band for TV and mobile broadband provisioning based on LTE cellular technology and infrastructure...
Article
Cognitive radio (CR) systems have been proposed for efficient usage of spare spectrum licensed to primary systems. This leads to the issue of providing as much spectrum to CR users as possible while not degrading the quality of service (QoS) of primary users of the spectrum. This paper proposes a novel cooperation scheme between primary and CR user...
Article
Wireless LANs based on the IEEE 802.11 standard are one of the most commonplace indoor wireless access solutions. As the ever growing demand for data consumption necessitates higher rates and volumes, it is fairly common to observe more and more WLANs being deployed in close proximity to each other. As distances between WLAN installations diminish,...
Conference Paper
Full-text available
This paper investigates the relationship between base station (BS) density and average spectral efficiency (SE) in the downlink of a cellular network. This relationship has been well known for sparse deployment, i.e. when the number of BSs is small compared to the number of users. In this case the SE is independent of BS density. As BS density grow...
Article
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The energy efficiency of wireless access networks has attracted significant interest, due to escalating energy cost and environmental concerns. How energy efficiency should be measured is, however, still disputed in the literature. In this letter, we discuss the impact of performance metrics and energy consumption models in network dimensioning. We...
Conference Paper
Full-text available
Mobile operators are facing an exponential traffic growth due to the proliferation of portable devices that require a high-capacity connectivity. This, in turn, leads to a tremendous increase of the energy consumption of wireless access networks. A promising solution to this problem is the concept of heterogeneous networks, which is based on the de...
Article
Full-text available
Cell discontinuous transmission (DTX) is a new feature that enables sleep mode operations at base station (BS) side during the transmission time intervals (TTIs) when there is no traffic. In this letter, we analyze the maximum achievable energy saving of the cell DTX. We incorporate the cell DTX with a clean-slate network deployment, and obtain opt...
Conference Paper
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Finding additional spectrum for indoor networks with very high capacity (ultra-dense networks, UDN) is a prime concern on the road to 5G wireless systems. Spectrum below or around 10 GHz has attractive propagation properties and previous work has indicated that vertical spectrum sharing between indoor users and outdoor wide-area services is feasibl...
Conference Paper
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As the number of TV-channels increase and the number of viewers per channel decreases, Terrestrial Broadcasting is becoming a less attractive way to distribute TV. In addition it does not represent a very efficient use of the UHF band (470-790 MHz). In this paper we discuss an alternative, converged platform for TV and mobile broadband provisioning...
Conference Paper
Indoor wireless LAN deployments have become ubiquitous. As WLAN deployments become increasingly dense, WLANs start to cause more and more contention and interference to each other, to the point that they cause significant throughput degradation to other WLANs. Since WLANs are one of the most commonplace solutions to provide indoor broadband data ac...
Article
In this paper, we analyze the feasibility of indoor broadband service provisioning using secondary spectrum access to the 960-1215 MHz band, primarily allocated to the distance measuring equipment (DME) system for aeronautical navigation. We propose a practical secondary sharing scheme customized to the characteristics of the DME. Since the primary...
Article
Full-text available
In this paper, we quantify the temporal opportunities for secondary access to radar spectrum. Secondary users are assumed to be WLANs which opportunistically share the radar frequency band under the constraint that the aggregate interference does not harm radar operation. Each WLAN device employs dynamic frequency selection (DFS) as a mechanism to...
Conference Paper
Full-text available
Energy efficiency in mobile radio networks has recently gained great interest due to escalating energy cost and environmental concerns. Rapidly growing demand for capacity will require denser and denser networks which further increase the energy consumption. In this regard, the deployment of small cells under macro-cellular umbrella coverage appear...
Conference Paper
Most of currently deployed Wi-Fi networks use the IEEE 802.11b/g standard and operate in 2.4 GHz ISMband. As mobile traffic demand rapidly increases, significant Wi-Fi deployment in the still very lightly used 5 GHz band is anticipated. In combination with the recent PHY amendments, e.g., 802.11ac, such Wi-Fi in many settings emerges as a strong co...
Conference Paper
Full-text available
In this paper, we present a quantitative assessment of the performance of a Wi-Fi like system in TV white space and compare it with the traditional Wi-Fi system in the ISM band. Particular emphasis is given to the constraint on the aggregate secondary interference on TV reception, which is regarded as the premise of the link throughput analysis tha...
Conference Paper
Cognitive radio (CR) systems have been proposed for efficient usage of spare spectrum licensed to primary systems. This leads to the issue of providing as much spectrum to CR users as possible while not degrading the quality of service (QoS) of primary users of the spectrum. This paper proposes a novel cooperation scheme between primary and CR user...
Conference Paper
Full-text available
In this paper, we provide a quantitative assessment of the available spectrum for massive indoor broadband secondary access in the 960-1215 MHz band, primarily allocated to the distance measuring equipment (DME) systems. We employ a practical sharing scheme where the secondary users share the DME spectrum via geo-location database and spectrum sens...
Article
Full-text available
As mobile IP-access is becoming the dominant technology for providing wireless services, the demand for more spectrum for this type of access is increasing rapidly. Since IP-access can be used for all types of services, instead of a plethora of dedicated, single-service systems, there is a significant potential to make spectrum use more efficient....
Article
Full-text available
Predictions for wireless and mobile Internet access suggest exponential traffic increase particularly in inbuilding environments. Non-traditional actors such as facility owners have a growing interest in deploying and operating their own indoor networks to fulfill the capacity demand. Such local operators will need spectrum sharing with neighboring...
Conference Paper
Full-text available
Mobile communication networks alone consume 0.5 percent of the global energy today. Rapidly growing demand for capacity will further increase the energy consumption. Thus, improving energy efficiency has recently gained great interest within the research community not only for environmental awareness but also to lower the operational cost of networ...
Conference Paper
Full-text available
The rapid growth in demand for mobile and nomadic wireless access forces the use of more and more base stations (BSs). In such dense networks, various techniques for multicell interference coordination have been investigated. However, whether or not the interference coordination provides cost benefit compared with a loosely coordinated system is no...
Article
Full-text available
Rapidly increasing traffic demand has forced indoor operators to deploy more and more Wi-Fi access points (APs). As AP density increases, inter-AP interference rises and may limit the capacity. Alternatively, cellular technologies using centralized interference coordination can provide the same capacity with the fewer number of APs at the price of...
Conference Paper
Full-text available
The potential of VHF/UHF band as a candidate for secondary spectrum access, so called “TV white spaces”, has been intensively investigated in recent years. However, the impact of the accumulated interference from multiple secondary users on different adjacent channels has not been well studied thus far, let alone the effect of combined interference...
Conference Paper
To maintain affordable access for the rapidly increasing mobile traffic, base station deployment has to be tailored to hot-spot areas and primarily indoors where facility owners, e.g., shopping malls or hotels, mostly provide wireless service. Since such local access providers (LAPs) do not have access to exclusive spectrum, one proposed option is...
Article
Full-text available
Secondary spectrum access, through which secondary users opportunistically access the underutilized radio spectrum, has emerged as a solution to cope with the perceived spectrum scarcity. The potential of secondary spectrum has therefore attracted industry players and regulators worldwide. To assess the real-life benefits of the secondary spectrum,...
Conference Paper
Full-text available
It is envisaged that diverse types of short-range wireless systems coexist in shared spectrum in a near future. For low-power systems, throughput and energy efficiency are two design objectives that often conflict with each other. In this paper, we investigate the tradeoff between the throughput and the energy efficiency for a data-hungry but batte...
Conference Paper
Full-text available
Mobile communication networks account for 0.5% of the global energy consumption, a value that is expected to double within the next five years. For this reason, means of reducing the energy consumption in cellular mobile radio networks has recently gained great interest within the research community. In mobile networks the backhaul contribution to...
Article
As the regulation in wireless communications is moving toward a more flexible and efficient way of managing radio spectrum, it is envisaged that multiple small-sized cellular networks owned by different operators, e.g., facility owners or local operators, will operate in close vicinity on shared spectrum. In this environment, the networks may compe...
Conference Paper
Full-text available
TV White space, where secondary systems can be deployed inside the TV coverage area and utilize the geographically unoccupied TV channels, is considered as a promising solution to relieve the spectrum shortage. To utilize this spectrum, the secondary users must ensure the protection of TV reception from harmful interference on both co-channel and a...
Conference Paper
Full-text available
Secondary spectrum access to TV white spaces is considered as a promising solution to relieve the spectrum shortage. In Europe, SE43 working group in CEPT is leading the discussion on the technical requirements for exploiting TV white spaces through the recent ECC report 159. Its analytical approach for determining the maximum permissible power for...
Conference Paper
Full-text available
Energy efficiency in cellular mobile radio networks has recently gained great interest in the research community. The development of more energy efficient hardware and software components aside, effect of different deployment strategies on energy efficiency are also studied in the literature. The latter mainly consist of optimizing the number and the...
Article
Full-text available
Multiple antenna systems can be used to enhance the perfor-mance of single links. However, it is still uncertain how to best utilize multiple antennas and multiple nodes at a system level. There are a number of techniques that show great promise at vastly improving the spectral efficiency of wireless systems; multi-hopping, coherent combining or co...
Conference Paper
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Dynamic spectrum sharing technique (“Cognitive Radio”) where secondary users opportunistically utilize temporarily or locally unused spectrum has emerged as a prime candidate technology to relieve the perceived spectrum shortage. Making a realistic assessment of the amount of spectrum available for secondary services is the objective of the EU FP7...
Conference Paper
A self-deployed network is considered to be one of cost-efficient deployment solutions by skipping an expensive network planning process. However, it may result in the serious degradation of capacity or the infeasibility of coverage constraint due to the rise of interference although radio adaptation techniques are employed. Therefore, deployment d...
Article
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We consider a slotted ALOHA setting where backlogged, energy-constrained users selfishly select the probability with which they transmit packets. Packets are successfully received, even in case of collision, if the signal to interference plus noise ratio at the access point exceeds some threshold (power capture). The user problem of finding appropr...
Conference Paper
Full-text available
As the regulation in wireless communications is moving toward a more flexible and efficient way of managing radio spectrum, it is envisaged that multiple small-sized cellular networks owned by different operators will operate in close vicinity on shared spectrum. This brings a new interference environment where a cell is interfered by not only base...
Conference Paper
Full-text available
This paper presents an analytical model to approximate the probability distribution function of the aggregate interference that a primary user receives from multiple secondary transmitters. In particular, we consider heterogeneity in spatial distribution of secondary users such that there are several sites with densely populated secondary users in...
Conference Paper
Full-text available
Energy Efficiency in cellular mobile radio networks has recently gained great interest in the research community. Besides the positive effect on global climate change, lowering power consumption of mobile networks is beneficial in terms of decreasing the operational cost for network operators. In this regard, the development of more energy efficien...
Article
The enhancement of cellular networks with relaying technologies is expected to bring significant technoeconomic benefits at the expense of more complex resource allocation. Suitable models for solving network dimensioning problems in cellular-relaying networks must handle radio resource allocation among hundreds of links and tackle interactions bet...
Conference Paper
Full-text available
Coordination of base stations is essential in the mitigation of inter-cell interference in cellular communication systems. One of practical solutions is a cluster-based inter-cell scheduling where base stations in each cluster determine their transmissions in cooperative fashion. In spite of potential performance improvement, the inter-cell schedul...
Conference Paper
Full-text available
In this paper, we investigate the spectrum sharing requirements of secondary access to 960-1215 MHz band which is primarily allocated to aeronautical usage. Primary system of interest is distance measuring equipments (DME) aiding navigation of airplanes. We consider a scenario where indoor femtocells share the spectrum as secondary users. For the p...
Article
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secondary user is prohibited from transmission if its individual interference to the primary user exceeds a certain threshold. Our model differs from existing work in the sense that the no-talk region has an irregular shape in the presence of the fading. We obtain the pdf of interference from an arbitrary secondary user. Then, we exploit the cumula...
Conference Paper
The presence of white spaces and spectrum holes in the TV bands represents potential opportunities for alleviating the apparent spectrum scarcity. Opportunistic spectrum access (OSA) has been proposed for the secondary user's operation and the main concern is the harmful interference that secondary systems could cause to the primary receivers. Exis...
Conference Paper
Full-text available
In this paper, we investigate the impact of aggregate interference in a secondary spectrum access system. Particularly, meteorological radar operating in 5.6 GHz band is considered to be a primary user. Secondary users are WLAN devices spreading in a large area which induce aggregate interference to the radar. We develop a mathematical model to der...
Article
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We formally define the gradual removal problem in wireless networks, where the smallest number of users should be removed due to infeasibility of the target-SIR requirements for all users, and present a distributed power-control algorithm with temporary removal and feasibility check (DFC) to address it. The basic idea is that any transmitting user...
Conference Paper
In order to maximize the network profit competitive service providers shall utilize their resources efficiently and price their services taking into account the demand responsiveness in the market. Pricing strategies play an important role in the network performance since they explicitly influence the user demand. Demand uncertainty would cause pro...
Conference Paper
Full-text available
In this paper we quantify the temporal opportunities for secondary access in radar bands. Secondary users are assumed to be WLANs which opportunistically access the radar spectrum. Each WLAN device employs dynamic frequency selection (DFS) as a mechanism to protect the radar from interference. We also consider an advanced interference protection me...
Conference Paper
It could be costly to deploy a full coverage mobile broadband service with high bandwidth for a single operator. The development of low cost radio network equipment for short range coverage could trigger off a new scenario. Some providers may invest heavily to provide coverage in a wide area, while other providers would invest considerably less to...
Article
Full-text available
In this paper we investigate the opportunistic spectrum access in temporal domain where a secondary user shares a radio channel with a primary user during the OFF period of the primary user. We consider practical ON/OFF traffic models whose bursty natures are not properly described by a Markovian assumption. An optimal strategy to determine the tra...