The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
System latency is one key metric that guides LTE design. Shortening TTI by reducing subframe length along with backward compatibility design can bring significant latency gains for legacy LTE systems. In general, it is believed that the shorter TTI is, the more gain can be achieved. However, due to the hardware limitation as well as the implementation complexity, it is not easy for ultra-short TTI...
Cell outage management is a self-healing functionality in future mobile cellular networks, aiming to automatically detect cell or site level outages (cell outage detection) as well as to mitigate as much as possible the caused degradation of coverage, capacity and/or service quality (cell outage compensation). Cell outage compensation has a variety of control parameters (and combination thereof) at...
This paper focuses on the performance evaluation of LTE uplink in presence of bursty data traffic. First, the performance of different power control (PC) strategies in different load conditions is evaluated. It is shown that the optimal PV policy depends on the load in the network and/or in the own cell. Simulation results demonstrate that in low load conditions applying no PC (or alternatively using...
The capacity and coverage area of a cell may vary due to changed environment, insertion or deletion of base stations, or malfunctioning base stations, and wrong parameter selection in the network planning phase. Suboptimal capacity and coverage area leads to the waste of network resources and the lower quality. Reacting on the changed situation manually is very expensive and time consuming. Therefore,...
Future cellular mobile radio networks will exhibit a much more dense base station deployment than 2nd or 3rd generation communications systems, particularly with regard to traffic coverage. Hence, a significant increase in power consumption of cellular networks can be expected. In order to counter this trend, energy efficiency of such networks should be increased considerably. Concerning energy efficiency,...
In many space communication scenarios high priority space traffic is received by a ground antenna and retransmitted via a ground link to a ground asset. In most instances this ground link supports multiple communication streams concurrently, and needs to multiplex the space traffic with these streams using a certain MAC layer protocol. By design, such MAC layer protocols will add a certain random...
In this paper we quantify 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) Release 8 downlink system performance for a macro cell hexagonal grid scenario. The system performance is analyzed for a closed loop Single User Multi-Input Multi Output (SU-MIMO) mode and compared with Single Input Multiple Output (SIMO) and Multi-User (MU) MIMO modes, for a full buffer scenario and static...
Mobile WiMAX is claimed to have the greatest potential of all wireless access technologies already in the markets with respect to network capacity, range, mobility, and quality of service support. Mobile WiMAX has also adopted MIMO as an essential element for increasing capacity and data propagation reliability. However, there are few publicly available studies demonstrating what is possible with...
This paper proposes a mathematical framework for comparing the performance of wireless networks based on the IEEE 802.11 standard, employing switched-beam, directional and adaptive antennas. The analysis adopts detailed models for the antenna system behavior and the propagation environment, taking into account multipath and interference. The purpose of this study is to determine the number of simultaneous...
Multipath routing can be effectively used to maximize the utilization of network resources for real-time traffic. In mobile ad-hoc network environments, this approach can suffer from co-channel interference due to the simultaneous transmission of packets via multiple routes. In this paper, by exploiting the directionality of directional antennas, a Directional Dynamic Source Routing (DDSR)-based Multipath...
Packet scheduling at the data link layer may impact significantly the overall performance of a wireless system using multiple antennas. In this paper, we propose a novel packet scheduling scheme based on proportional fairness that considers the traffic arrival process with different packet lengths for the downlink of multiple-input multiple-output (MIMO) multi-user systems. We also provide analysis...
Mobile WiMAX as an OFDMA (Orthogonal Frequency Division Multiple Access) mobile broadband air interface is a solution to the requirements for mobile internet services. It has been accepted by ITU as 3G standard last year. The work presented in this paper focuses on evaluation of the Mobile WiMAX system performance in which Full-Queue and VoIP traffic are considered both in downlink and uplink We have...
In this paper we present the results on performance evaluation of 6-sector-site deployment and compare against 3-sector-site deployment in the downlink UTRAN LTE systems. To facilitate the performance evaluation a quasi-dynamic multicell system level simulator that follows the 3GPP UTRAN LTE specifications has been used. A significant gain in the order of 88% in site capacity is achieved by changing...
A promising approach for improving the capacity of Wireless Mesh Networks is by making use of multiple non-overlapping RF channels. Multi-channel protocols have the advantage that several devices can transmit in parallel within a collision domain on distinct channels. When using IEEE 802.11b/g/a most protocol designers assume 3 and 12 non-overlapping channels, respectively. However, this simplified...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.