WCDMA uplink system performance

Featuring edge caching and computing, fog radio access networks have been seen as promising architectures. However, the joint optimization of cache and radio resource can put heavy burden on the resource manager in the cloud. To overcome this issue, hierarchical radio and cache resource management is studied in this paper. The core idea is to fully utilize the resource management capabilities of fog access points (FAPs) to divide time-domain resource on a small timescale by participating a coalitional game while make the resource manager allocate cache resource on a large timescale to maximize a long-term utility. Based on defined FAP preference, a low-complexity and distributed coalition formation algorithm is first developed under per-FAP fronthaul capacity constraints. Then, facing the challenges incurred by no closed form, discrete variables and the curse of dimensionality, multi-agent reinforcement learning (MARL) based caching is proposed for the resource manager. In the proposal, multiple agents are created, one for each content-FAP pair, who jointly learn a caching strategy via the interaction with a history network environment. By simulation, the effectiveness of the MARL based caching is demonstrated.

The ever increasing user QoS demands and emergence of new user applications make job of network operators and manufacturers more challenging for efficiently optimisation and managing radio resources in radio the radio resources pools of different wireless networks. A group of strategies or mechanisms which are collectively responsible for efficient utilisation of radio resources available within the Radio Access Technologies (RAT) are termed as Radio Resource Management (RRM). The traditional RRM strategies are implemented independently in each RAT, as each RRM strategy considers attributes of a particular access technology. Therefore traditional RRM strategies are not suitable for heterogeneous wireless networks. Common Radio Resource Management (CRRM) or joint radio resource management (JRRM) strategies are proposed for coordinating radio resource management between multiple RATs in an improved manner. In this paper a fuzzy algorithm based CRRM strategy is presented to efficiently utilise the available radio resources in heterogeneous wireless networks. The proposed CRRM strategy balances the load in heterogeneous wireless networks and avoids the unwanted congestion situation. The results such as load distribution, packet drop rate and average throughput at mobile nodes are used to demonstrate the benefits of load balancing in heterogeneous wireless networks using proposed strategy.

As heterogeneous networks (HetNets) emerge as one of the most promising developments toward realizing the target specifications of Long Term Evolution (LTE) and LTE-Advanced (LTE-A) networks, radio resource management (RRM) research for such networks has, in recent times, been intensively pursued. Clearly, recent research mainly concentrates on the aspect of interference mitigation. Other RRM aspects, such as radio resource utilization, fairness, complexity, and QoS, have not been given much attention. In this paper, we aim to provide an overview of the key challenges arising from HetNets and highlight their importance. Subsequently, we present a comprehensive survey of the RRM schemes that have been studied in recent years for LTE/LTE-A HetNets, with a particular focus on those for femtocells and relay nodes. Furthermore, we classify these RRM schemes according to their underlying approaches. In addition, these RRM schemes are qualitatively analyzed and compared to each other. We also identify a number of potential research directions for future RRM development. Finally, we discuss the lack of current RRM research and the importance of multi-objective RRM studies.

This paper describes and evaluates a novel 2‐dimensional radio resource allocation scheme for high‐throughput cellular packet data access. The proposed system employs spread spectrum orthogonal frequency division multiplexing with adaptive time and frequency allocation (SS‐OFDM‐F/TA) of radio resources. In order to achieve high spectral efficiency of downlink packet transmissions to multiple mobile users, multi‐user diversity available in the multi path fading environment is exploited through the use of adaptive modulation and coding, best serving sector selection, suitable scheduling of packet transmissions and hybrid ARQ employing soft‐packet combining and incremental redundancy. The data throughput, packet delay and fairness of the system with slow and fast best sector selection are examined. A method of grouping disjoint sub‐bands for use in highly frequency‐selective environments is described and evaluated. Packet re‐transmission options including a proposal of several asynchronous re‐transmission algorithms and constraining the maximum re‐transmission interval are also considered. It is demonstrated that the proposed spread spectrum OFDM system is capable of reaching a spectral efficiency of about 1.7 b/sec/Hz/sector with single receive and transmit antennas, and seems to provide a promising solution for high‐throughput best‐effort delay‐tolerant data services in future cellular radio systems. Copyright © 2004 AEI

This chapter revisits many of the issues concerning radio resource management with a focus on the upcoming systems embodying the Coordinated Multipoint (CoMP) technology. Nowadays CoMP-based systems have attracted special attention due to their potential benefits in terms of spectral efficiency and coverage. As a part of 3GPP Long Term Evolution—Advanced, CoMP technology promises substantial improvement of the users’ experience at the expense of requiring a reliable and efficient connection among the evolved Node Bs (eNBs). If multiple users and eNBs are coordinated using a suitable technique, the concerns about interference can be greatly alleviated and, consequently, also the restrictions on sharing the radio resources. In this chapter, the grouping of users and eNBs is explored in two different occasions. First, coordinated strategies process the Channel State Information (CSI) for scheduling users in order to improve the system performance; afterwards, clustering of eNBs is described as an attractive approach to deal with the processing and signaling overheads brought by CoMP. The chapter presents an analysis of different algorithms, as well as case studies illustrating some key concepts through computer simulations.

The consideration of realistic uplink inter-cell interference is essential for the overall performance testing of future cellular systems, and in particular for the evaluation of the radio resource management (RRM) algorithms. Most beyond-3G communication systems employ orthogonal multiple access in uplink (SC-FDMA in LTE and OFDMA in WiMAX), and additionally rely on frequency-selective RRM (scheduling) algorithms. This makes the task of accurate modeling of uplink interference both crucial and non-trivial. Traditional methods for its modeling (e.g., via additive white Gaussian noise interference sources) are therefore proving to be ineffective to realistically model the uplink interference in the next generation cellular systems. In this article, we propose the use of realistic precomputed interference patterns for LTE uplink performance analysis and testing. The interference patterns are generated via an LTE system-level simulator for a given set of scenario parameters, such as cell configuration, user configurations, and traffic models. The generated interference patterns (some of which are made publicly available) can be employed to benchmark the performance of any LTE uplink system in both lab simulations and field trials for practical deployments. It is worth mentioning that the proposed approach can also be extended to other cellular communication systems employing OFDMA-like multiple access with frequency-selective RRM techniques. The proposed approach offers twofold advantages. First, it allows for repeatability and reproducibility of the performance analysis. This is of crucial significance not only for researchers and developers to analyze the behavior and performance of their systems, but also for the network operators to compare the performance of competing system vendors. Second, the proposed testing mechanism evades the need for deployment of multiple cells (with multiple active users in each) to achieve realistic field trials, thereby resulting in significant cost (and time) savings in the field trails.

This article provides an overview of radio resource management (RRM) in the context of network slicing considering a range of different deployment options and practicalities. Initially, it elaborates the 3GPP radio access network (RAN) sharing in terms of business and architecture. Slice‐tailored RRM solutions are then considered for various base station deployments focusing on RRM principles and customization, which result in different paradigms of resource sharing including full isolation, sharing, and hybrid approaches. The concept of slice broker is also elaborated, which aims to allocate radio resources related to slice requests considering the desired service performance, highlighting the need of traffic and mobility forecasting. The notion of resource sharing is further analyzed, considering various RRM and scheduling schemes including multi‐objective and hierarchical RRM, slice‐aware flexible function split, TDD service‐oriented solutions, and joint radio and backhaul optimization and licensed assisted configurations.

Long Term Evolution (LTE) standard aims for high data rate transmission in the order of several hundreds of Mbps. Non-Orthogonal Multiple Access (NOMA) transmission is proposed in LTE-Advanced (LTE-A) systems to increase the cell throughput. NOMA based transmission allows the eNodeB (eNB) to multiplex the different users' signals in power domain in a frequency-time grid. In this paper, a novel Hybrid Automatic Repeat and reQuest (HARQ) scheme is proposed for NOMA based transmission. In the proposed method, power level of users are adjusted dynamically in re-transmissions in order to reduce the number of attempts for successful transmission of packets. This will increase the overall cell throughput and reduce power consumption at UE. The proposed method is applied on the Incremental Redundancy (IR) form of HARQ scheme. System level simulations are carried out by considering LTE system parameters. Based on the results, the proposed method improves the cell throughput by reducing the number of retransmissions in HARQ process considerably.

The evolution of cellular networks from one generation to another has led to the deployment of multiple radio access technologies (such as 2G/2.5G/3G/4G) in the same geographical area. This scenario is termed heterogeneous cellular networks. In heterogeneous cellular networks, radio resources can be jointly or independently managed. When radio resources are jointly managed, joint call admission control algorithms are needed for making radio access technology selection decisions. This chapter gives an overview of joint call admission control in heterogeneous cellular networks. It then presents a model of load-based joint call admission control algorithm. Four different scenarios of call admission control in heterogeneous cellular networks are analyzed and compared. Simulations results are given to show the effectiveness of call admission control in the different scenarios. The coexistence of different cellular networks in the same geographical area necessitates joint radio resource management (JRRM) for enhanced QoS provisioning and efficient radio resource utilization. The concept of JRRM arises in order to efficiently manage the common pool of radio resources that are available in each of the existing radio access technologies (RATs) (Perez-Romero et al, 2005). In heterogeneous cellular networks, the radio resource pool consists of resources that are available in a set of cells, typically under the control of a radio network controller or a base station controller. There are a number of motivations for heterogeneous wireless networks. These motivations are (1) limitation of a single radio access technology (RAT), (2) users’ demand for advanced services and complementary features of different RATs, and (3) evolution of wireless technology. Every RAT is limited in one or more of the following: data rate, coverage, security-level, type of services, and quality of service it can provide, etc. (Vidales et al, 2005). A motivation for heterogeneous cellular networks arises from the fact that no single RAT can provide ubiquitous coverage and continuous high QoS levels across multiple smart spaces, e.g. home, office, public smart spaces, etc. Moreover, increasing users’ demand for advanced services that consume a lot of network resources has made network researchers developed more and more spectrally efficient multiple access and modulation schemes to support these services. Consequently, wireless networks have evolved from one generation to another. However, due to huge investment in existing RATs, operators do not readily discard their existing RATs when they acquire new ones. This situation has led to coexistence of multiple RATs in the same geographical area.

Nowadays, The Long-term Evolution-advanced (LTEA) system is widely used to provide the fifth generation (5G) communication network due to its improved network capacity and less delay during the communication process. The main issues in 5G network are insufficient resources of users and Burst errors, because it creates losses in the data transmission, in order to overcome this effective radio resource management to be developed in the 5G network. In this paper the binary crow search algorithm is proposed to develop the radio resource management in the 5G network. The proposed radio resource management is used for assigning adequate power and bandwidth to the desired user equipments of the network. In radio resource management a request queue is used for avoiding the unwanted resource allocation in the network. Moreover, the losses during the Transmission are minimized by using frequency Interleaving and Guard level Insertion. The performance of the proposed system is analyzed in terms of bit rate and sum rate.KeywordsQuality-of-Service (QoS)Long-term evolution (LTE)Data rateRadio resource organization approach (RROA)Long-term evolution-advanced (LTE-A)

The efficiency of a WiFi system with dozens of base stations in relatively small physical area is determined by the optimal allocation of the radio channels to the mobile devices. Based on the increased penetration rate of the high traffic capable smartphones and accentuated usage of these devices in densely populated buildings intelligent hardware tools are needed to offer QoS level to the users. The Radio Resource Management (RRM) of IEEE 802.11 network is provided by a wireless LAN controller. This node maintains an allocated control connection to each of the base stations providing enhanced quality level of the WiFi hot zone services. Modern base stations have the capability to listen to the radio channels periodically to detect the received signal intensity. The controller samples periodically each of the radio channels without affecting the own radio frame processing and collects in this way radio resource usage. Based on specific criteria like the number of active nodes, traffic intensity, interference, noise intensity the periodically executed RRM management algorithm modifies the distribution of active channels on the supervised hot zone level. The radio signal intensity scanning task is considered to be performed by the base stations as a sampling process of individual sensors distributed in physical space. Eighteen WiFi access points with thirteen channel sensors in 2.4 GHz range and sixteen channel sensors in 5 GHz range were used to capture radio signal intensity in a densely populated building. Holding special criteria in the scanned signal intensity values is considered as a complex event. Clustering method based on similarity measure was used to analyse sensor grouping behavior of the wireless controller RRM algorithm. Our work is focused on the usability of different statistical metrics (i.e. Hurst, Davies-Bouldin, etc.) to characterize intrusion detection efficiency of the wireless LAN controller.

In the context of 5G systems, the emergence of various use cases with diverse requirements has attracted great attention to network slicing. In a single physical network, several instances of logical end-to-end networks, i.e. slices, will be instantiated to fulfill these requirements. To this end, slices should share the resources of the physical network, which consist of Core Network (CN) and Radio Access Network (RAN) resources. Herein, we focus on the Radio Resource Management (RRM) in the context of network slicing. To maximize the pooling gains, dynamic resource sharing is preferred over static sharing. However, dynamic resource sharing can lead to undesirable inter-slice influences, in particular, the contention on radio resources. In this article, we show that, although the radio resources are dynamically shared among the users of different slices, proper slice management can realize slice protection. This is achieved by adjusting the fraction of radio resources allocated to the different slices by the Packet Scheduler (PS) and by limiting the number of users admitted to the network via Admission Control (AC). We propose an iterative algorithm to optimize the parameters of PS and AC in order to ensure that the service level agreements are satisfied. Extensive system-level simulations have shown that a central entity that tunes these control parameters can greatly increase the network's performance.

This paper discusses load balancing architecture among heterogeneous wireless networks (HWNs). Load balancing is an important issue for efficient use of radio resources not only in a single network but among different radio access technologies (RATs) in HWNs. Cooperative management of radio resources among heterogeneous RATs is considered to reduce imbalance of utilization of radio resources and enhance availability of the system. For effective load balancing, we define a ldquocommunityrdquo concept, in which radio resources of various RATs are managed together. Radio resource management functional entities of RATs cooperatively work in the community. We present a load balancing architecture applied to 3GPP LTE, WiBro and WLAN and describe architectural considerations. We also present a straightforward load balancing algorithm that takes account of bandwidth usage and received signal to noise ratio. The load balancing algorithm of community radio resource management enhances utilization of radio resources and reduces call blocking probability of individual RATs in the community and further enhances average performance of the whole community.

This paper investigates the radio resource management (RRM) approaches for GSM/GPRS networks. The effort was put on access control (AC), time-slot (TS) allocation, and radio link control (RLC) packet scheduling for down-link performance enhancement. A new credit-based algorithm was proposed and implemented in a system level simulator. The simulation results for overall cell throughput as well as throughput per user show an improvement for the proposed scheme in comparison to a best effort algorithm, in particular in high-load scenarios.

The Worldwide Interoperability for Microwave Access and Long Term Evolution is a telecommunications technologies aimed at providing wireless data over long distances in a variety of ways based on the IEEE 802.16 standard. This paper presents radio resource management and performance analysis for WiMax and LTE by using RRM (Radio Resource Management) methods. Providing a comparison between different traffics (e.g. video (streaming), data and voice) for multimedia communication systems (3G), the paper offers different standpoints that can satisfy a researchers looking for theoretical analysis and advanced algorithms or searching for their concrete application in the real networks. The paper also demonstrates the importance of the radio resource management (RRM) in a wireless communication networks for OFDMA systems. We concentrate our study in the reservation of the radio resources according the Rayleigh channel. Multipath Rayleigh channel EModel is useful in wireless communications (IEEE 802.16e). These phenomena include multipath scattering effects, time dispersion, and Doppler shifts that arise from relative motion between the transmitter and receiver.