Optimized delay threshold scheduler for multimedia traffic over LTE downlink network

The success of the smart grid majorly depends on the advanced communication architectures. An advanced smart grid network should satisfy the future demands of the electric systems in terms of reliability and latency. The latest 4th-generation (4G) wireless technology, the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE), is a promising choice for smart grid wide area networks (WAN), due to its higher data rates, lower latency and larger coverage. However, LTE is not a dedicated technology invented for smart grid, and it does not provide Quality of Service (QoS) guarantee to the smart grid applications. In this paper, we propose an optimal LTE uplink scheduling scheme to provide scheduling timeguarantee at the LTE base station for different class of traffic, with a minimal number of total resource blocks. A lightweight heuristic algorithm is proposed to obtain the optimal allocation of resource blocks for each class of traffic. In the simulation, we compare the proposed optimal scheduling scheme and two existing scheduling schemes, the Large-Metric-First scheduling scheme and the Guaranteed Bit Rate (GBR) /Non-GBR scheduling scheme. The comparison results demonstrate that the proposed optimal scheduling can use less resource blocks to satisfy the scheduling time requirements than the other two existing scheduling schemes.

Wireless technologies have become the model for Entertainment, Communication and Education all over the world. Electrical and Electronics Engineering Departments of various Universities across the globe offer courses on Wireless Communication and Networks for Undergraduate and Postgraduate students by focusing on the latest teaching pedagogy. Recent advancements in health care services demand reliable transmission of medical images and videos for better diagnosis and treatment. The effective utilization of available spectrum is one of the requirements for stable transmission of medical information. A Long Term Evolution (LTE) system model for a real-time multimedia application must provide high Quality of Service (QoS). Scheduling and allocating resources for real-time downlink flows in LTE networks is a challenging issue, as the network excellence and assured output have to be confirmed together with decreasing the Head of Line (HOL) suspension. The ever increasing demand for higher data rates in uplink and downlink transmission services constraints on delay and bandwidth requirements. This leads the existing fourth generation LTE wireless networks to concentrate more on the resource scheduling techniques with acceptable levels of Quality of Service (QoS). In this paper, a Game theory based scheduling (GTBS) and resource allocation Algorithm multimedia traffic in LTE network is designed and studied. The Algorithm is simulated in LTE-sim for real time (RT) and Non-real time (NRT) data traffic. The work identified a new teaching pedagogy, the work is explained to the undergraduate Engineering students so that they can apply the knowledge to develop new innovative projects.

One of the key features of the fifth-generation (5G) cellular network is non-orthogonal multiple access (NOMA) which improves the spectrum efficiency and increases the network connectivity. A second key ingredient is device to device (D2D) communication which increases spectrum efficiency and off-loads the cellular network. A proper exploitation of both NOMA and D2D requires adequate resources allocation algorithms to manage the interference. Moreover, to support various quality of service (QoS) requirements, other key metrics beyond the rate should be taken into account, such as queue stability and head of line (HoL) packet delay. In this paper, we consider resource block (RB) allocation and power control for both uplink NOMA and D2D communications. An overlay spectrum sharing paradigm is adopted, where an RB is exclusively allocated to either the cellular or D2D communications. The solution uses the modified largest weighted delay first (MLWDF) scheduling discipline and reduces the HoL packet delay, with negligible reduction of the achieved sum rate with respect to the pure maximum-rate solution in typical cellular scenarios.

In the Cellular Long-Term Evolution (LTE) downlink, the smallest radio resource unit a Scheduler can assign to a user is a Resource Block (RB). Each RB consists of twelve (12) adjacent Orthogonal Frequency Division Multiplexing (OFDM) sub-carriers with inter-subcarrier spacing of 15 kHz. Over the years, researchers have investigated the problem of radio resource allocation in cellular LTE downlink and have made useful contributions. In an earlier paper for example, we proposed a deterministic dynamic programming based technique for optimal allocation of RBs in the downlink of multiuser Cellular LTE System. We found that this proposed methodology optimally allocates RBs to users at every transmission instant, but the computational time associated with the allocation policy was high. In the current work, we propose a truncated dynamic programming based technique for efficient and optimal allocation of radio resource. This paper also addresses uncertainty emanating from users’ mobility within a Cell coverage area. The objective is to significantly reduce the computational time and dynamically select applicable modulation scheme (i.e., QPSK, 16QAM, or 64QAM) in response to users’ mobility. We compare the proposed scheme with the Fair allocation and the earlier proposed dynamic programming based techniques. It is shown that the proposed methodology is more efficient in allocating radio resource and has better performance than both the Fair Allocation and the deterministic dynamic programming based techniques.

Two-stage coalition formation and radio resource allocation with Nash bargaining solution for inband underlaid D2D communications in 5G networks

Handover (HO) algorithms, managed by Mobility Management Entity (MM), and Scheduling algorithms, managed by Radio Resource Management Entity (RRM) are both the most important aspects in the next-generation cellular systems 3GPP Long Term Evolution (LTE). When a User Equipment (UE) is in motion, the constraints of offering better Quality of Service (QoS), especially in Real Time applications, increase. This is why the design of a powerful handover algorithm is essential, in order to ensure a seamless transfer of a UE to a new cell. In this article, we propose a new HO algorithm based on the Available Bandwidth prediction at the eNBs level. The improvements proposed by our scheme compared to other HO algorithms such as LTE Hard Handover Algorithm (LHHA), Integrator Handover and LTE Hard Handover Algorithm with Average RSRP Constraint (LHHAARC) has been shown via different parameters namely throughput, system delay and Packet Loss Ratio (PLR). Using LTE-Sim simulator, all HO algorithms were simulated against the three well-known scheduling schemes, namely, Proportional Fair (PF), Exponential Proportional Fairness (EXP / PF) and Modified Largest Weighted Delay First (MLWDF). The objective is to define a synthesis allowing the automatic choice of the proper scheduling scheme to use, according to the HO decision algorithm predefined by the system.

Quality of Service (QoS) is defined as user’s satisfaction towards service performance that has been offered to them. Due to different traffic characteristics and QoS requirements of real-time and non-real-time services, thus provisioning the QoS requirements has become a challenge. In this study, we have compared our proposed algorithm namely the Exponential Blind Equal Throughput (EXP-BET) towards the Exponential Proportional Fairness (EXP-PF) and Frame Level Scheduler (FLS). The comparisons have been made in terms of fairness index, throughput,packet loss rate (PLR) and delay. From the simulation results, it is observed that EXP-BET delivers higher fairness and throughput and lower PLR and delay for real-time application. Instead, EXP-BET shows 17.72% improvement than FLS and 7.52% from EXP-PF in term of fairness index for the non-real-time application.

We consider in this paper downlink scheduling at the Medium Access Layer (MAC) layer for delay sensitive traffic in wireless systems based on Orthogonal Frequency Division Multiple Access (OFDMA). We refer in particular to next generation wireless systems such as 3GPP-LTE. We propose an Opportunistic Packet Loss Fair (OPLF) scheduling algorithm based on calculating a simple dynamic priority function which depends on the Head of Line (HOL) packet delay, the packet loss rate (PLR) and the achievable instantaneous downlink rate of each user. This algorithm overcomes the main limitations of existing algorithms, achieving better performance than state-of-the art algorithms, such as Modified Largest Weighted Delay First (M-LWDF), Proportional Fair (PF), and Packet Loss Fair (PLF), in terms of throughput, PLR and fairness among users.

One of the critical components of the Smart Grid (SG) is the Smart Meter (SM), which reports power consumption to a centralized control center at regular intervals. The Long Term Evolution (LTE) network has received much attention as a promising platform for SG communications due to its high bandwidth and low latency over a large coverage area. Nevertheless, when a huge number of SMs access the LTE network, the preamble collision becomes an issue. The negative effects of preamble collision are packet loss, delay, reestablishment attempts, and physical channel utilization, which degrade the performance of the LTE network. Hence, a Random Access (RA) mechanism is required for preamble signature to occupy Resource Blocks (RBs) for SMs. In this paper, we introduce a hybrid procedure that combines contention and non-contention based random access methods. The significance of this method is that, although SMs have fixed periodic communications, preamble signatures do not need to be reserved. The simulation results are compared with LTE standard. Packet loss is reduced by approximately 43%. SM latency is decreased by 11 ms at 90% of probability delay. Re-establishment attempts are lower than standard by proximately 76%. Finally, physical channel utilizations are reduced by around 3%.

This paper describes an open system architecture that allows independently developed hard real-time applications to run together and supports their reconfiguration at run-time. In the open system, each real-time application is executed by a server and scheduled by a two-level hierarchical scheduler. At lower level, the OS scheduler schedules all the servers on the EDF basis. At the upper level, the server scheduler of each server schedules the ready jobs of the application that the server executes according to the algorithm chosen for the application. The two-level scheduler never accepts a real-time application that may not be schedulable in the open system, and once it accepts a real-time application, it guarantees the schedulability of the application regardless of the behaviors of other applications in the system. The paper also describes the design and implementation of the open system within the framework of the Windows NT operating system. The implementation consists of three key components: the two-level hierarchical kernel scheduler, common system service providers, and real-time application programming interface.

Owing to the randomness of the job release time, it is not possible to obtain all job information in real time during the operation of a manufacturing system. Generating a suitable scheduling strategy at the correct moment is the focus of addressing this disturbance. In this study, the flow time of the job in the manufacturing system was used as a criterion for evaluating the performance of the scheduling strategy. Subsequently, a model was constructed for selecting the optimal dispatching rule (DR) to actively change the scheduling strategies during the production process. The constructed model for selecting the optimal DR included an initial model for selecting the optimal DR and an evaluation model. The initial model for selecting the optimal DR outputs a DR with better performance based on the attributes of the job to be scheduled in the manufacturing system. Meanwhile, the evaluation model is responsible for evaluating the DR output of the initial model for selecting the optimal DR and determining whether the DR needs to be updated; the update process is realized based on simulation technology. Following experimental verification, the constructed model could generate scheduling strategies with superior performance in real-time and realize the update of the historical database. The results of this study will be of reference significance for solving the disturbance problem encountered by the manufacturing system in real time.

Long Term Evolution (LTE) is a main mobile communication technology in the future. For the reason that different kinds of multimedia applications have different quality of service (QoS) requirements, especially for Real Time (RT) traffics, it is necessary to design an effective scheduling algorithm to satisfy the various kinds of QoS needs. In this paper we propose a new scheduling algorithm named DP-VT-MLWDF. The simulation results of the proposed scheduler indicate an evident improvement of the QoS performance parameters for RT traffics, e.g., packet loss rate, average throughput, fairness index.

Long Term Evolution (LTE) network deploys Orthogonal Frequency Division Multiple Access (OFDMA) technology for downlink multi-carrier transmission. To meet the Quality of Service (QoS) requirements for LTE networks, packet scheduling has been employed. Packet scheduling determines when and how the user’s packets are transmitted to the receiver. Therefore effective design of packet scheduling algorithm is an important discussion. The aims of packet scheduling are maximizing system throughput, guaranteeing fairness among users, andminimizing either or both PacketLoss Ratio (PLR)and packet delay. Inthis paper, the performance of two packet scheduling algorithms namely Log Maximum-Largest Weighted Delay First (LOG-MLWDF) and Max Delay Unit (MDU), developed for OFDM(Orthogonal Frequency Division Multiplexing)networks, has been investigated in LTE downlink networks, and acomparison of those algorithmswith a well-known scheduling algorithm namely Maximum-Largest Weighted Delay First(MLWDF) has been studied.The performance evaluation was in terms of system throughput, PLR and fairness index. This study was performed forboth real time (voice and video streaming)and non-real time (best effort)perspectives. Results show that for streaming flows,LOG-MLWDF shows best PLR performance among the considered scheduling schemes, and for best effort flows, it outperforms theother two algorithms in terms of packet delay and throughput.

Streaming media technology is also known as streaming media technology. Users can experience playing while downloading function, which improves the transmission speed of multimedia information on the internet. In this paper, we use streaming media technology, combined with the parabolic interpolation and Newton interpolation algorithm, design multimedia interactive platform of the college students' ideological and political education and comprehensive education. The overall structure of the platform is composed of multimedia, streaming media distribution equipment, school network, clients of teachers and students. On the internet between the teachers and students, student and students they can communicate ideological and political. In order to test the performance of network, we use the iperf software to test packet loss rate and delay characteristics of the network. The results show that Newton interpolation method has better delay characteristics, parabolic interpolation algorithm has low packet loss rate. It provides technical reference for the application of multimedia technology in the ideological and political education.

With limited frequency allocation in the radio spectrum, spectral efficiency has always been the core development of communication systems. To accommodate the increase in demand for wireless data services, RF systems have been challenged to provide better in-channel SNR (EVM) and lower out-of-channel emission. As performance requirements become more stringent, second-order RF circuit impairments, that were previously insignificant, have become major design considerations. One example is the Long-Term-Evolution (LTE) [1]. Compared with previous generations, channel bandwidth has been expanded to 9MHz in most of the sub-GHz bands and 18MHz in the GHz bands. For spectral efficiency, the TX OFDM subcarriers are grouped into Resource Blocks (RBs) that can be dynamically allocated within the channel bandwidth. Noise and spurious emission requirements have become more challenging in the sub-GHz bands, so that Counter 3d-order Intermodulation products (CIM3) has been recognized as an important design parameter [2-4] for LTE RF systems. CIM3 is the result of the lower 3d-order intermodulation (IM3) product of signals at around 1×LO and 3×LO by using mixers with 25% or 50% duty-cycle LO. If an f BB tone is being fed to the TX baseband input, after the mixer and the RF amplifier, the TX RF output will produce the desired signal tone at f LO +f BB and an unwanted CIM3 tone at f L0 -3f BB [3]. The adverse effects of CIM3 are shown in Fig. 9.7.1, using LTE Band 13 as an illustration. Band 13 has User-Equipment (UE) TX band from 777 to 787MHz, and RX band at −31 MHz away from TX. Extreme cases of full RB and single RB are considered. At full RBs, modulated CIM3 has a bandwidth three times the desired signal, and it folds directly into the TX channel, degrading the TX EVM and the 1st ACLR (E-UTRA). Furthermore, the ACLR of bandwidth-expanded CIM3 falls into the RX band causing desensitization. When single RB is transmitted, the CIM3 may fall into the restricted bands and violate the spectral emission requirement. Consider the Public Safety Band, where the LTE standard dictates that the emission from 769 to 775MHz has to be less than −57dBm/6.25KHz [1]. If the output power at the antenna is +23dBm and only single RB is being transmitted, the power density is 23dBm/180kHz. Normalizing to power density from 180KHz to 6.25KHz, the power density is 8.4dBm/6.25KHz, resulting in a CIM3 requirement of −65.4dB/6.25KHz. This is challenging for linearity, and also for noise requirement in the case of a SAW-less system. CIM3 suppression techniques such as harmonic rejection and power mixing have been proposed [2-5], but these techniques require extra calibrations and/or off-chip filtering components, which will be described in later paragraphs. This work presents a CIM3 suppression technique by removing the undesired 3rd-harmonic component in the LO signal through LO duty-cycle selection. With this direct root-cause elimination method, the TX meets CIM3 and RX band noise requirements for SAW-less LTE RF systems over process and temperature without calibration and off-chip filtering.