A Framework for Multiaccess Support for Unreliable Internet Traffic using Multipath DCCP

Communication networks beyond 3G will see the interconnection of heterogeneous radio access networks in order to always provide the best quality of service in the most efficient way to users with multi-mode terminals. This scenario poses a number of critical issues, which have to be faced in order to get the best from the integrated network. In this paper we investigate the issue of parallel transmission over multiple radio access networks: in particular we propose simple but effective radio resource management algorithms, whose performance is investigated by means of a simulative approach in UMTS-IEEE802.11a and IEEE802.16e-IEEE802.11a heterogeneous networks (adopted as case studies). An insight on TCP level critical aspects, strictly related to the parallel transmission over multiple access networks, is also provided.

The relationship between the user perceived Quality of Experience (QoE) with Internet applications and the Quality of Service (QoS) of the underlying network and applications is complex. Unveiling statistical relations between QoE and QoS can boost the prediction and diagnosis of QoE. In this paper, we shed light on the relationship between QoE and QoS for a popular application: YouTube video streaming. We conducted a controlled study where we asked users to rate their perceived quality of YouTube videos under different network conditions. During this experiments, we also captured network QoS and application QoS. We then analyze the resulting dataset with SES, a feature selection algorithm that identifies multiple, minimal-size, statistically-equivalent signatures with maximal predictive power for a target variable (e.g., QoE). We found that we can build optimal QoE predictors using a minimal signature of only three features from application or network QoS metrics compared to four when we consider features from both layers.

This work proposes a novel dynamic and adaptive yet fair spectrum allocation policy to be adopted by a service provider (SP). Here, we consider a scenario where a single SP owns multiple access networks (ANs) of different (not necessarily competing) technologies. We conceive that an SP employs an entity, called local spectrum controller (LSC), which manages the common pool of spectrum and is responsible for distributing the spectrum to individual ANs in a fair manner. Since the available spectrum is insufficient to satisfy the aggregate demand from all ANs simultaneously, LSC has to resort to a dynamic spectrum allocation technique. We have modeled the problem as an n-player cooperative bankruptcy game and have solved the problem with the help of Shapley value. We have proposed a suitable utility function for the AN with respect to its received spectrum and have identified possible objectives of LSC (i.e., SP) namely, maximizing equality of distribution (MED) and maximizing proportional fairness (MPF). We have proposed a novel equal utility distribution (EUD) algorithm that maximizes our MED objective. Finally, we have studied performances of EUD, Shapley value and max-min fairness algorithm with respect to the above objectives and have compared with nucleolus solution concept.

Traditionally wireline network and wireless network have been operated and managed separately. Future network will provide converged network service on wireline and wireless networks together. Service requirement for unified access to both wireline and wireless networks emerged as we experience more sophisticated network services. This paper discusses a unified access control for 5G convergence network with multiplicity of different access networks. With minor change onto Dynamic Host Configuration Protocol (DHCP) we can reuse authentication information among various access technologies on 5G convergence network. The proposed method enables us to reuse authentication information from one access network onto another access network. Authentication reuse and unified access control will reduce complexity of 5G convergence network access procedure with multiple access networks and provide consistent access procedure regardless what access technology a user chooses to use.

VoIP application.The theoretical analysis evaluated the multipath transmission model and verified that the Latent Handover can efficiently optimize the handover process and enhance transmission efficiency during handover.Extensive simulations under different scenarios verified that the multipath mechanism can effectively enhance VoIP transmission and mobility efficiency.

In this study, the performance of wirelessly powered relay‐aided non‐orthogonal multiple access networks is investigated in terms of outage probability. Specifically, two relay selection strategies, i.e. two‐stage relay selection (TRS) and maximum energy harvesting relay selection (MEHS), and two energy harvesting scenarios, i.e. time switching (TS) and power splitting (PS) are considered. In each setup, outage probabilities' analytical expressions and their asymptotics are derived. Monte‐Carlo simulations are also carried out to verify the correctness of the analysis. The results show that regardless of relay selection and energy harvesting strategies, increasing transmit power can improve the proposed system performance. However, TRS can achieve a full diversity order, while MEHS has a unit diversity order. Besides, the results recommend parameter selections of PS and TS coefficients for optimal performance in term of outage probability.

We present a general framework for distributed wireless information flow allocation problem in multiple access networks, where the end users (EUs) can seek wireless flows from multiple access points (APs). We aim to minimize the power consumption while satisfying each EU's minimum data rate requirement but not violating peak power constraint of each AP and interference constraint monitored by regulatory agents. Toward this end, we model the flow allocation problem as a game which is proved to be a best-response potential game. Then based on potential game theory, we show the existence and uniqueness of Nash equilibrium in the formulated game. Moreover, we demonstrate that the Nash equilibrium is actually the globally optimal solution to our problem. Besides, we propose two distributed algorithms along with convergence analysis for the network to obtain the Nash equilibrium. Meanwhile, we reveal the interesting layered structure of the problem in question. Extensive numerical results are conducted to demonstrate the benefits obtained by flow allocation, as well as the effectiveness of our proposed algorithms.

Facing the ever-increasing demand for high quality video streaming and the dramatic variations of wireless network environment, adaptive bitrate video streaming (ABS) emerges as a prominent video quality adaptation technique in improving users' quality of experience (QoE). Reinforcement learning (RL)-based ABS and network-assisted ABS can improve users' QoE through resource utilization efficiency enhancement. However, limited network capacity is still the bottleneck of QoE improvement. Considering the potential capacity gain of non-orthogonal multiple access (NOMA), we study network-assisted ABS in NOMA networks. Based on a synchronous video streaming model and the knowledge of channel state information for next segment, a joint optimization problem of resource allocation and bitrate adaptation is formulated to maximize users' QoE and minimize energy consumption. The original problem is NP-hard and intractable due to the interference coordination problem introduced by NOMA and the multi-slot sum rate constraint. We decompose the original problem into the subproblem of joint subchannel assignment and power allocation (JSAPA), and the subproblem of bitrate adaptation (BA) with Lagrange relaxation method. A joint resource allocation and bitrate adaptation (JRABA) algorithm is further proposed to solve the JSAPA and BA subproblems iteratively. Specifically, the JSAPA subproblem is solved by an extended Gale-Shapley matching algorithm and differ of convex (DC) programming method iteratively. For the BA subproblem, appropriate video bitrate is explored with subgradient method. Numerical results validate the effectiveness of the proposed algorithm and reveal that network-assisted ABS in NOMA networks benefits users in achieving higher QoE with less energy consumption, especially when radio resources are insufficient or with large segment size.

This paper investigates the physical layer security issue in an amplify-and-forward (AF) multi-input multi-output (MIMO) two-way relay assisted cognitive radio (CR) nonorthogonal multiple access (NOMA) network, where the simultaneous wireless information and power transfer (SWIPT) technology is employed to improve network energy efficiency. We consider the scenario that a pair of primary users and two pairs of secondary users (SUs) exchange information via a MIMO two-way relay, where the edge SU of each SU pair is untrusted and tries to wiretap the central SU’s information. For ensuring security, we aim to maximize the sum achievable secrecy rate (SASR) by jointly optimizing the power allocation at all users, power splitting factor and relay beamforming subject to the quality of service (QoS), energy harvesting and transmit power constraints. The formulated optimization problem is highly nonconvex due to coupling variables, thus it is challenging to solve. An effective path-following (PF)-based algorithm is proposed, which is proven to converge to a stationary point. Theoretical and simulation results show that the proposed PF-based algorithm has lower complexity than the state-of-art algorithm. To further reduce complexity, we proposed a zero-forcing (ZF)-based scheme. Numerical simulations show that the proposed PF-based algorithm achieves the same SASR as the state-of-art algorithm with moderate complexity, while the proposed ZF-based scheme strikes a good balance between performance and complexity.

This paper investigates the secure transmission in hybrid automatic repeat request (HARQ)-assisted non-orthogonal multiple access (NOMA) networks, where a security-required (SR) user is paired with an opportunity-served (OS) user to perform NOMA. Different from the previous works where NOMA and HARQ are separately considered for secure transmissions, in this paper, both NOMA and HARQ are utilized to enhance the security of the SR user. We derive the closed-form expressions for connection outage probability (COP), secrecy outage probability (SOP), reliable and secure transmission probability (RSP) and effective secrecy throughput (EST) of the SR user in both maximum ratio combining (MRC) and selection combining (SC) schemes. The security-reliability trade-off (SRT) results of the SR user in both MRC and SC schemes are also provided. Analysis and simulation results show that HARQ improves secrecy performance in MRC and SC schemes in terms of RSP, especially in low transmit power region. Besides, since every retransmission is utilized in the MRC scheme, it strictly outperforms the SC scheme in terms of the SRT metric. However, the SC scheme has the potential to achieve higher EST than the MRC scheme by optimizing the transmit power or the power allocation factor. Significantly, the quality of service (QoS) of the OS user can be guaranteed by pairing an SR user who is far away from the transmitter and the secrecy performance of the SR user can be enhanced by pairing an OS user.

we design novel code-division multiple access (CDMA) networks which use strict optical orthogonal codes (OOCs) and incoherent optical processing for multichannel variable-bit-rate (VBR) video broadcasting. The proposed techniques possess the characteristics of fast access tunability and bit-rate flexibility. This in turn can facilitate real-time VBR video distributions for entertainment HDTV applications. Compared with conventional OOCs, the use of strict OOCs can ensure both auto- and cross-correlation constraints to be minimum (i.e., "1") for multichannel VBR video broadcasting and high-speed photonic switching applications. A parallel-serial hybrid architecture for all-optical tunable decoders (or encoders) is also presented to strict OOCs, which has a fast reconfiguration time to support real-time video applications in high-speed optical fiber CDMA networks.

Local Area Network Communications Using Optical Spread Spectrum and Serial Correlation of Bipolar Codes

We investigate a novel robust flow control framework for heterogeneous network access by devices with multi- homing capabilities. Towards this end, we develop an H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> -optimal control formulation for allocating rates to devices on multiple access networks with heterogeneous time-varying characteristics. H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> analysis and design allow for the coupling between different devices to be relaxed by treating the dynamics for each device as independent of the others. Thus, the distributed end-to-end rate control scheme proposed in this work relies on minimum information and achieves fair and robust rate allocation for the devices. An efficient utilization of the access networks is established through an equilibrium analysis in the static case. We perform measurement tests to collect traces of the available bandwidth on various WLANs and Ethernet. Through simulations, our approach is compared with AIMD and LQG schemes. In addition, the efficiency, fairness, and robustness of the H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> -optimal rate controller developed are demonstrated via simulations using the measured real world network characteristics.

In this paper, we study the relay transmission of uplink non-orthogonal multiple access (NOMA) network in terms of performance analysis. Specifically, two users applying NOMA scheme intent to transmit the message to base station (BS) by the help of amplify-and-forward (AF) relay. The expressions of outage probability and throughput for two users are derived based on the statistical characteristics of signal-to-noise ratio (SNR) and signal-to-interference-plus-noise ratio (SINR) of transmission links by using Gaussian-Chebyshev quadrature method. In order to look into the behaviour of this considered system, the numerical results are provided using system key parameters, e.g., transmit power, distances. The Monte-Carlo simulation results are also provided to verify the correctness of our analysis.

Fiber optic code-division multiple access (FO-CDMA) networks using optical series coupler access encoders (SCAEs) and series coupler access decoders (SCADs) are analyzed considering the higher order signals of the optical matched filter. By mathematically interpreting the inevitable interference effect of the higher order signals up to the third order, we found that the performance of the FO-CDMA networks could be seriously degraded due to the sidelobe peaks increased by the higher order signals. We also found that the interference signal intensities increase according to the increase of coupling coefficient (?). Compared with the conventional analysis without considering the higher order signals, the peak-to-sidelobe ratio considering the higher order signals is degraded, for example, by 3.75 dB for N(coupler number) = 5, ? = 0.5, and the code length of 341.