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Cross-border coordination of radiocommunications services is a very important aspect of spectrum engineering, crucial for network feasibility in countries' border areas. It is an ongoing activity, with a purpose to assure uninterrupted operation of different (or the same) radiocommunications networks between two or more neighboring countries. The ever-growing introduction of new technologies and services...
Frequency reuse factor in LTE network is 1 meaning that the total available bandwidth is used in every cell. Intra-cell interference in the downlink direction is mitigated via orthogonality. Interference is therefore dominated by inter-cell interference, especially at the cell edge. In order to measure the impact of the inter-cell interference, and thus weight the importance and necessity for inter-cell...
Efficient utilization of open spectrum in cognitive radio networks requires appropriate allocation of idle spectrum frequency bands among coexisting cognitive radios while minimizing interference among all primary and secondary users. This NP-hard problem is referred to as the spectrum allocation or the channel assignment problem in cognitive radio networks. This article proposes and tests an enhanced...
The advent of cognitive radio technology will enable user terminals with adaptive access to licensed and unlicensed portions of the spectrum. This will improve end-user satisfaction and will partially alleviate the bandwidth scarcity problem. However, different parts of the spectrum not only have different network (e.g. radio and load) conditions, but also different licensing and/or billing agreements...
Multi-tier networks comprising of macro-cellular network overlaid with less power, short range, home base stations like femtocells provide an economically feasible method for increasing the cellular capacity. Also the benefit of femtocells is found more in downlink since the traffic in downlink is several times more than in uplink. However, the femtocells share the same licensed frequency spectrum...
Device-to-device communication (D2DC) is an important and challenge technique in the next generation of wireless communication that it can effectively reduce the load of base stations and simultaneously allows user equipment (UE) to proceed in direct communications. In D2DC, devices are very close among themselves and therefore the resulting interferences maybe quite serious, it becomes an important...
The Department of Defense (DoD) is developing policy-based spectrum management (PBSM) concepts, architectures, and capabilities to improve DoD's use of the electromagnetic spectrum, particularly in the area of edge networking. This use of PBSM is a paradigm shift in the way DoD will manage the use of the electromagnetic spectrum in support of Dynamic Spectrum Access (DSA) enabled Policy Based Radios...
The Department of Defense (DoD) is currently engaged in a broad set of research and development efforts relating to the technical, operational, regulatory, and standardization of Dynamic Spectrum Access (DSA) capabilities for mission related applications. DoD is converging on the use of a policy-based management approach as the fundamental source of situational awareness for DSA radios to base their...
The demand for spectrum is growing rapidly as data intensive mobile communications and high-definition television are getting more popular. The spectrum regulators are preparing for flexible spectrum use and the implementation of new technologies. To make the appropriate decisions, the regulators need to identify and evaluate the different alternatives. In this paper, we examine a systematic classification...
Simulation approaches and results are provided for Dynamic Spectrum Access (DSA) with remote wide-area spectrum monitoring equipment and moderate delay in spectrum data dissemination. Issues expected to arise using this approach include information delay time, failure to detect all transmitters, transmitter location errors, poor transmit-power estimates, and errors in the propagation model used to...
Long Term Evolution (LTE) technology is considered as the most possible candidate for next generation mobile communications. LTE networks offer high capacity and are specified and designed to accommodate small, high performance, power-efficient end-user devices. One limiting factor that influences LTE performance is the interference from neighbor cells, the so called Inter-Cell Interference (ICI)...
Metro cells are an emerging solution to improving hotspots throughput in cellular networks. Unfortunately, they cannot be deployed in a large scale under current cellular networks because of a severe interference problem. We propose a new metro-cell base station control switch (BSCS) which reconfigures topologies and frequency bands adapting to changing traffic demands. The new BSCS connects distributed...
In this paper, we consider a cellular cognitive radio network that uses opportunistic spectrum access for its transmission in the downlink direction from base stations toward cognitive radio users. Since the spectrum is licensed to a primary network, proper resource management should be employed in the secondary network to protect primary users against excessive interference while providing acceptable...
In order to suppress cross-tier interference (CTI) and inter-cell interference (ICI) between adjacent macrocells, this paper proposes an effective resource allocation scheme for the two-tier OFDMA femtocell networks, in which macro BSs adopt the soft frequency reuse (SFR) strategy. Consider that macrocell users (MUEs) are prior to femtocell users (FUEs), firstly the subbands are allocated to MUEs...
Femtocells are low power access points that can be deployed by the consumer indoors to alleviate cellular coverage problems, offload traffic from the cellular network and boost user data rates. To enable the widespread of femtocells coexisting with macrocells, smart interference management schemes are required. Interference management by frequency allocation is still a big challenge in hybrid macro/femto...
The current mobile communication environment is advancing rapidly with 3G networks' data rates growing and LTE representing already the preliminary version of the ITU-R-defined fourth generation. While the 3G and LTE development provides a new era for the multimedia communications with considerably higher bit rates and lower latencies, the legacy systems as 2G are still important as their market share...
In this paper, we propose a new cell architecture for the orthogonal frequency division multiple access (OFDMA) systems by jointly taking frequency allocation scheme (FAS) and cooperative relay strategy into consideration. To serve the mobile stations (MSs) in the inner zone and relay stations (RSs) in the outer zone, a larger portion of frequency spectrum is allocated to the central base station...
Relay Based Cellular Networks (RBCNs) are a key development in cellular networking technology. However, because of ever increasing demand and base station failure, RBCNs still suffer from user congestion and low resilience problems. This paper proposes two competing solutions: dynamic frequency allocation and antenna tilting to those problems. Firstly a new dynamic fractional frequency allocation...
In cellular systems, Fractional Frequency Reuse (FFR) partitions each cell into two regions; inner region and outer region and allocates different frequency band to each region. Since the users at the inner region are less exposed to inter-cell interference, the frequency resources in each inner region can be universally used. Based on this frequency band allocation, FFR may reduce channel interference...
This paper considers the problem of dynamic spectrum allocation (DSA) in the adjacent regions controlled by each spectrum broker (SB). In this scenario, the SB has a responsibility to allocate the spectrum to network service providers (NSPs) in region that SB controls. However, the SB cannot manage the interference arising between regions, and, therefore, the quality of allocated spectrum cannot be...
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