Radio Resource Allocation

Underlaying Device-to-Device (D2D) communications can increase the spectral efficiency of cellular networks when sharing part of the spectrum with cellular users. This requires radio resource allocation policies capable to limit and control the interference between D2D and cellular communications. Many of the proposed policies are centralized, and require the base station to decide which resources should be allocated to each D2D transmission. Centralized schemes can efficiently control interference levels, but their feasibility can be compromised by their complexity and signaling overhead. To address this constraint, this paper proposes DiRAT, a distributed radio resource allocation scheme for D2D communications underlaying cellular networks. With DiRAT, the D2D nodes locally select their radio resources from a pool created by the cellular network in order to control the interference generated to the primary cellular users. DiRAT includes a control mechanism to ensure that the user QoS requirements are satisfied. This study demonstrates that DiRAT can increase the network capacity while avoiding or limiting the degradation of the performance of the primary cellular users. DiRAT also significantly reduces the complexity and overhead compared to existing centralized and distributed schemes.

Device-to-Device (D2D) communications can increase the spectral efficiency of future cellular networks when sharing part of the cellular spectrum. Radio resource allocation mechanisms are then necessary to control the interference that D2D and cellular transmissions can generate to each other. Most of the existing allocation schemes rely on the knowledge of the channel gain of all possible links between cellular and D2D nodes. This paper proposes to reduce the complexity cost and signalling overhead of the allocation process by using location information available at the network level. Using this information, the base station assigns radio resources to new D2D transmissions with the objective to control and limit the interference to the primary cellular users and existing D2D transmissions. The proposed radio resource allocation scheme continuously monitors that the user QoS requirements are satisfied. If it is not the case, it dynamically modifies the resource allocation to the interfering D2D transmissions. The proposed scheme achieves performance levels similar to that obtained with an optimized centralized allocation scheme, but with a significantly lower complexity cost and signaling overhead.

Our paper introduces a new efficient resource allocation algorithm, based on a priority function considering the precedence class, the waiting time in the BSC buffer, the QoS historic evolution and the communication quality of each mobile station. The results have been obtained for GPRS context, and the evaluation of our new allocation scheme is carried on using a cellular network simulator. Our discrete-time simulation tool takes into account both the time variation of the system and its spatial dimension which characterizes both the user mobility in the cellular covered area and the signal propagation impairments since the vast majority of mobile communication systems operate in an around centers of population. In this paper we consider users supporting GPRS/UMTS multimedia applications.

Device-centric wireless technologies, such as Device-to-Device (D2D) communications, will provide new ways of connectivity and significant opportunities to enhance the capacity and efficiency of 5G networks. Underlaying D2D communications will share radio resources with cellular communications and novel radio resource management schemes need to be defined to control the interference between D2D and cellular nodes. This paper proposes a distributed radio resource allocation scheme for D2D communications underlaying cellular networks. The proposed scheme allows D2D nodes to select radio resources from a pool identified by the infrastructure to limit the interference caused by D2D links to cellular communications. The proposed scheme includes a control process in order to guarantee that user QoS requirements are satisfied. The conducted study demonstrates that the proposed scheme significantly improves spectral efficiency of traditional cellular systems while guaranteeing QoS requirements to both cellular and D2D communications.

In this paper the performance of radio resource allocation in GSM/GPRS network is analyzed. A two dimension Markov chain is presented using guard channels for handover calls. Also priority is given on reservation of QoS of voice service by applying priority for voice calls to pre-empt GPRS data packets.

Radio resource allocation in OFDMA can exploit multiuser diversity to increase system capacity by implementing opportunistic scheduling and resource management techniques. This paper presents a new opportunistic subcarrier management scheme for OFDMA-based wireless multimedia networks. The scheme targets the class of delay-sensitive packets that belong to interactive applications. The subcarrier management is done in two steps: the OFDMA subcarrier allocation and subsequently the subcarrier assignment. Both the sub-carrier allocation and assignment algorithms exploit multi-user diversity and are designed to provide fairness with respect to the realizable per user performance. We compare the performance of the proposed algorithm with static OFDM-FDMA assignment with actual MPEG-4 traffic traces under different system loading and requested deadline values. The results show the superiority of the proposed scheme and its excellent performance with respect to throughput, packet dropping,...

Layer 2 radio resource allocation schemes being used in mobile ad hoc networks do not always take into account the Quality of Service (QoS) requirements of network traffic. As an example, the current USAP (Unifying Slot Assignment Protocol) slot ...

In this article, we investigate a resource allocation problem for multicarrier multiuser MISO (multiple-input-Single-output) downlink systems, where multiple co-channel multicast groups are served simultaneously. We consider a rate-splitting transmission scheme to address the inevitable inter-group interference under an overloaded multigroup multicast scenario, where the insufficient number of transmit antennas prevents the conventional schemes from neutralizing the interference. We first formulate an optimization problem for maximizing the minimum multicast group rate among all groups on all available subcarriers. This problem involves a joint power and subcarrier allocation optimization, and is non-convex. We apply an iterative scheme based on successive convex approximation (SCA) to find the locally optimal solution. Simulation results demonstrate the performance gain of the proposed scheme compared to the state-of-the-art transmission schemes.

Network flows running on a wireless mesh network (WMN) may suffer from partial failures in the form of serious throughput degradation, sometimes to the extent of starvation, because of weaknesses in the underlying MAC protocol, dissimilar physical transmission rates or different degrees of local congestion. Most existing WMN transport protocols fail to take these factors into account. This paper describes the design, implementation and evaluation of a coordinated congestion control (C3L) algorithm that guarantees fair resource allocation under adverse scenarios and thus provides end-to-end max-min fairness among competing flows. The C3L algorithm features an advanced topology discovery mechanism that detects the inhibition of wireless communication links, and a general collision domain capacity re-estimation mechanism that effectively addresses such inhibition. A comprehensive ns-2-based simulation study as well as empirical measurements taken from an IEEE 802.11a-based multi-hop wireless testbed demonstrate that the C3L algorithm greatly improves inter-flow fairness, eliminates the starvation problem, and at the same time maintains high radio resource utilization efficiency.