The advent of 5G technology has revolutionized network communication by introducing network slicing (NS) and virtualization to allow multiple network service providers (NSPs) to share infrastructure, thereby reducing deployment costs and accelerating 5G adoption. While this new open marketplace enables NSPs to trade resources dynamically, it also exposes the system to security concerns, such as front-running and selfish-validation attacks, which can lead to market manipulation and strategy leakage. This paper presents TRADE-5G, a secure blockchain-based marketplace for 5G resource trading that mitigates these attacks and ensures fair, transparent resource allocation while preserving the confidentiality of NSP strategies. Through extensive simulations, TRADE-5G demonstrates a substantial 18% improvement in user satisfaction and a 36% reduction in wasted resources compared to traditional models. Additionally, it opens new profit opportunities for NSPs through unused resources, establishing a more competitive, secure, and transparent 5G trading environment that exceeds the capabilities of traditional mobile networks.

The aim of this paper is to introduce a new Internet generation designed for 6G readiness. The 6G architecture is envisioned to rely on trust zones, termed as 'Edges'. Each Edge comprises nodes that incorporate small-scale data centers, enabling a significant portion of 6G queries to be processed locally. This local setup introduces distributed data centers within the Edge nodes that can be as small as embedded into a smartphone and facilitates serverless functions. Edge nodes proliferation offers 6G to create a new kind of infrastructure where nearby edge nodes can be accessed directly, in Device-to-Device (D2D) mode, rather than via the traditional vertical Internet architecture. 6G will therefore be made up of vertical, long-distance communications and short, horizontal distribution channels. The vertical aspect of the network is represented by the telecommunication operator’s infrastructure, which provides secure channels between trust zones. The horizontal network is a new domain addressed by both incumbent players and new entrants called the Internet of Edges [6]. The 'Cloud Continuum' encapsulates both horizontal and vertical networks. 6G like Internet of Edges infrastructure has been developed, tested, and is currently being commercialized by Green Communications.

Recent advances in wireless technology and embedded systems enable vehicles to share relevant traffic-related data to improve the transportation Quality-of-Service (QoS). However, due to the ubiquitousness of cyber-attacks, it is challenging to ensure the integrity of the data collected from cars. This paper proposes a novel architecture for road traffic events management in Vehicular Ad hoc NETworks (VANETs) relying on a permissioned blockchain . It also introduces the concept of micro-transactions to minimize communication and storage overhead . Through simulations, a rigorous performance evaluation of the proposed approach was conducted, and the micro-transactions effectiveness was assessed. In addition, a comparison with close works in the literature was performed. The proposed scheme ensures road traffic records integrity and traceability, and simulation results on the considered scenarios showed good performance .

In recent years, studies have been conducted to evaluate the performance of blockchain-based technologies to solve various problems. In this paper, we present a proof of concept in which we evaluate the robustness of a blockchain-based application in an ad hoc network confronted with split merge problems that may be caused by node mobility. We highlight how a blockchain should behave according to the network state and we measure its cost in terms of network load. We show that the measurements depend greatly on the mining algorithm used to solve the consensus.

Energy consumption has become a key issue in the design of communication systems. Indeed, both for economic and green reasons, the concept of energy saving appears at an early stage of projects, fully integrating the list of expected performance, as well as throughput or security. In multihop wireless networks, several energy-aware approaches have been proposed with specific goals, such as network's lifetime or stability. To reduce the global energy consumption of such networks, we proposed in a previous work an optimal solution with interference consideration, based on mixed integer linear programming, to route a set of flows over a minimal number of nodes. Thus, without degrading flow rates, inactive nodes can be put in a sleep mode or be turned off to maximize energy savings. Indeed, the energy consumption related to communication is just a fraction of the total consumption of a node In this article, we are going a step further, by providing a metric to efficiently aggregate flows with classical shortest path algorithms. Thanks to a theoretical comparison and simulations, we demonstrate the significant gains can be obtained with our approach. Finally, we discuss on ways to implement our solution in existing routing protocols, in a fully distributed manner, and other considerations that may need to take on.

The security mechanisms for Long Term Evolution (LTE) networks are essential between User Equipment and eNodeB to prevent diverse threats and attacks. Data confidentiality and Data integrity are the main inevitable features for any secure communication system. Thus the 3GPP has standardized till now three pairs of algorithms (EEA1, EIA1), (EEA2, EIA2) and (EEA3, EIA3) for LTE security. In this paper, a new efficient DI algorithm based on a keyed hash function called ERDIA is introduced. Accordingly, the use of key and message dependent diffusion layers ensure the key sensibility and the avalanche effect using only one processing round. The experimental results show that the proposed hash function is immune against most possible known attacks. Besides, a lower computational time is attained compared to EIA2. Furthermore, our proposition would be similarly well suited for other networks and applications such as wireless networks.

Recently, several encryption schemes have been presented to Random Linear Network Coding (RLNC). The recent proposed lightweight security system for Network Coding is based upon protecting the Global Encoding Vectors (GEV) and using other vector to ensure the encoding process of RLNC at intermediate nodes. However, the current lightweight security scheme, presents several practical challenges to be deployed in real applications. Furthermore, achieving a high security level results in high computational complexity and adds some communication overhead. In this paper, a new scheme is proposed to overcome the drawbacks of the lightweight security scheme and that can be used for RLNC real-time data exchange. First, the cryptographic primitive (AES in CTR mode) is replaced by another approach that is based on the utilization of a new flexible key-dependent invertible matrix (dynamic diffusion layer). Then, we show that this approach reduces the size of communication overhead of GEV from 2 × h to h elements. In addition to that, we also demonstrate that besides the information confidentially, both the packet integrity and the source authentication are attained with minimum computational complexity and memory overhead. Indeed, cryptographic strength of this scheme shows that the proposed scheme has sufficient security strength and good performance characteristics to ensure an efficient and simple implementation thus, facilitating the integration of this system in many applications that consider security as a principal requirement.

The security of Wireless Sensor Networks (WSN) is essential for effective deployment in various areas and applications such as military and business. The existing security solutions of WSN are based on multi-round function, which requires high computing complexity and energy consumption. WSN have, however, limited resources that prevent their efficient deployment for a long period. In this paper, a new kind of security system based on a cipher and authentication algorithm called EDCA is presented to ensure the necessary security requirements with low computation complexity. Furthermore, the proposed cipher is based on a dynamic binary diffusion layer. The contents of packets is divided into many blocks, which are mixed together to produce the cipher blocks. Likewise, an enhanced version of cipher is presented to attain a better statistical properties. Additionally, EDCA is evaluated by comparing it with AES, which is considered reliable and robust in several standards of sensor networks. The results show that the proposed algorithm has a reduced computation complexity, and is robust and could be adopted for different types of wireless or mobile networks.

Random Linear Network Coding (RLNC) is a promising technology of Network coding (NC) {that is} verified to be both sufficient and efficient. In this paper, we propose an efficient implementation of coding process, ensuring the security against active and passive attacks, in order to deploy RLNC in real networks, especially on battery constrained mobile devices with low computation capabilities such as mobile phones or sensors. We first present our flexible secure solution that can achieve simultaneously the information confidentiality, the packet integrity and the source authentication. It contains a new scheme of generation of invertible key dependent binary Global Encoding Matrix (GEM) with a complexity, a memory consumption and a decoding delay lower than the traditional $RLNC$. The effectiveness of coding process is proved by modifying the Galois field of calculation from integer (int8, int16) to binary in order to ensure low computational requirements that lead to high throughput and low energy consumption. Furthermore, theoretical and numerical results reveal that the proposed methods give an effectiveness of coding and a higher level of security compared to many recent works in this field.

In this paper, a new ciphering algorithm is proposed for Long Term Evolution (LTE) data confidentiality. The proposed cipher scheme is based on a novel stream cipher framework which uses Substitution-Diffusion (SD) structure to provide key-streams that possess acceptable cryptographic performance (avalanche effect and key sensibility). Standards have been already adopted by 3GPP for LTE data confidentiality; EEA1, EEA2, and EEA3 which are based on Snow 3G, Advanced Encryption Standard (AES), and ZUC, respectively. Although the above mentioned algorithms have sufficient security strength against attacks, our solution is constructed to ensure less complexity with similar security strength. The proposed algorithm consists of an addition layer and a modified RC6 substitution layer which could require no memory and has stronger cryptographic properties compared to RC6. Furthermore, a new dynamic non-invertible diffusion layer technique is introduced, which is constructed from the output of the substitution layer. Theoretical and simulation results show that our algorithm is immune against liner, differential, chosen/known-plain-text, brute force and statistical attacks. Equally important to note, our proposed cipher algorithm has a lower computational time compared to AES, and could be adapted for other kinds of wireless networks.

We consider the channel access problem in a multi-channel opportunistic communication system with imperfect channel sensing, where the state of each channel evolves as an independent and identically distributed Markov process. The considered problem can be cast into a restless multi-armed bandit (RMAB) problem that is of fundamental importance in decision theory. It is well-known that the optimal policy of RMAB problem is intractable for its exponential computation complexity. A natural alternative is to consider the easily implementable myopic policy that maximizes the immediate reward but ignores the impact of the current strategy on the future reward. In this paper, we perform an analytical study on the optimality of the myopic policy under imperfect sensing for the considered RMAB problem. Specifically, for a family of generic and practically important utility functions, we establish the closed-form conditions to guarantee the optimality of the myopic policy even under imperfect sensing. Despite our focus on the opportunistic channel access, the obtained results are generic in nature and are widely applicable in a wide range of engineering domains.

Most of the works on Generation-Based Network Coding (GBNC) consider a fixed generation size. A large generation size maximizes the Network Coding benefits but leads to a long delay while a small generation size reduces the delay but decreases the throughput. This paper presents the DYnamic GEneration Size (DYGES) approach. Our network-aware method adjusts the generation size according to the network variations (network size, congestion, losses) for multicast flows to keep the delay steady. Our goal is to guarantee a Quality of Service (QoS) in terms of delay. The simulation results show the accuracy of DYGES.

Network Coding is a recent technique that has many advantages such as reducing the bandwidth consumption and increasing the throughput. IROCX [1] is a routing algorithm that applies Network Coding while considering the interference impact. However, it assumes a constant transmission power. We extend IROCX by allowing the nodes to transmit with several power levels. Our approach, TC-IROCX (Topology Control on Interference-aware Opportunistically Coded Exchanges) aims at maximizing the number of accepted flows. The simulation results show that TC-IROCX adjusts the transmission power according to the network state in order to enhance the acceptation rate.

This paper considers a multicast scenario and compares the average reception quality obtained when combining multiple description coding (MDC) and network coding (NC). Plain (single description) network coding (NC-SDC) serves as reference. In the considered scenario, a single source is multicast to several receivers with various channel conditions. Contrary to a NC-SDC scheme, unable to recover the coded packets when not enough combinations of packets have been received, NC of MDC packets allows a more progressive quality improvement with the number of received packets, and a reduction of the effect of the quantization noise when MDC is performed via frame expansion before quantization. Considering a probability distribution for the bit transition probability during transmission to any user in the multicast group, the expected signal-to-noise ratio is evaluated. Performance comparisons are made for various error distributions, field sizes, and MDC methods (via frame expansion and correlating transform).

Network Coding is a new field that aims at, notably increasing the throughput in a network. ROCX [1] is an algorithm that makes routing with the awareness of network coding. However, its major limitation is that it does not take into account the bandwidth limitation and the interference impact. If the interference is not considered in a wireless network, a flow requiring a certain bandwidth might be accepted and see its throughput decreasing due to interference. In this case, the Quality of Service (QoS) is not respected. Therefore, we use the clique-based model of I2ILP [2] to introduce constraints that consider interference. We present in this paper IROCX, a routing algorithm for wireless mesh networks. It uses Linear Programming for routing while maximizing the benefits of Network Coding and considering interference. The simulation results show the effectiveness of our algorithm.

We propose a novel distributed coding scheme for broadcast over ad-hoc wireless networks. In this scheme, all nodes perform coding using a simple rateless code over the previously received, generated, or decoded symbols. Rather than waiting for a full block of encoded packets to be received before intermediate nodes could decode and resend coded packets, we design a new degree distribution that enables the intermediate nodes to start decoding even when small number of encoded packets are received. Thus, we decrease the delay introduced at the intermediate nodes because of decoding and then re-encoding. The main advantage of using a kind of rateless code for encoding instead of using a random linear combination of the previously received packets is to reduce significantly the encoding and decoding complexities. We provide a performance evaluation using a simulation to demonstrate the efficiency of our code in term of reducing the number of transmissions and increasing the delivery ratio.

In this paper, we present a novel rateless code which outperforms LT-code, since it is adapted for network coding. To reduce the delay incurred at the intermediate nodes because of decoding and re-encoding, we design and analyze a novel degree distribution which we call Switched Distribution. This distribution increases the delivery ratio at the decoder even when few encoded symbols are received. The performance of our scheme is evaluated using simulations.

Since sensor nodes use batteries as their source of energy, energy-based routing becomes an important requirement to extend network lifetime. This routing is done using the nodes remaining energy information. Nonetheless, this information cannot be estimated using built-in primitives in nodes powered by a lithium-ion battery. In this paper, we introduce an efficient battery model that estimates the remaining energy of a node independently of its battery chemistry. Our model is based on an existing battery model that uses the current consumption during a state and its duration to estimate the battery remaining energy. The original model is very accurate, however, it cannot be implemented in a sensor node as it requires complex computations and large lookup tables. Therefore, we present a recursive approximation of this model that requires low memory and simple computation, while maintaining the original model accuracy. Through extensive real battery discharge measurements, we demonstrate the accuracy of our model and in addition, we show that the ideal model widely used to estimate sensor nodes remaining energy is not accurate.

This paper presents a theoretical estimation for idle channel time in a multi-hop environment. Idle channel time is the time proportion of a node during which the channel state is idle. Thus, it can be used to evaluate the available bandwidth. Major related work considers a cross-layer model, where the idle channel time measure is available at the MAC layer, but it is rarely implemented. Furthermore, this measure is not very flexible: it cannot differentiate the traffic's priorities and it works under the hypothesis that flows are strictly policed. Estimating instead of measuring the idle channel time prevents these drawbacks. This estimation is computed in three steps by (1) calculating the idle channel time bounds, (2) evaluating the probability of a given idle channel time value, (3) computing the expected value of this distribution and deducing the average idle channel time. We show by simulation that our estimation is accurate.

In the present work we examine the impact of average path-delay routing (APDR) to TCP, in 802.11 ad hoc networks. The route discovery is based on the lowest average-delay path, and on optimised link state routing (OLSR). The simulation study on ad hoc scenarios reveals an improved roundtrip time (RTT) for TCP, but a reduced throughput. As shown, regular route oscillation events cause packet reordering. Thus, only the delay as a routing metric is not sufficient to improve TCP. We apply an APDR optimisation, i.e., a path reservation scheme, in order to avoid route oscillations in static ad hoc networks. Thus, APDR outperforms standard OLSR and improves the TCP throughput. The results of the present study yield for a descent controling algorithm, to avoid the multi-path effect.

We address the problem of estimating the remaining energy of a node's battery in wireless sensor networks. To solve this issue, we provide an on-line battery model that requires limited memory and low computational complexity. The accuracy of our battery model is verified by simulation.

This paper studies the unfairness issues of network coding in multi hop wireless networks. Most of the work on network coding focuses on the obtained throughput gain. They show that mixing lineally the packets at the intermediate nodes is capacity-achieving. However, network coding schemes designed only to maximize the throughput could be unfairly biased. The reason is that by mixing different flows, packets destined to one destination in order to be decoded need to wait for the reception of the whole mixed set of encoded packets that may be totally independent in terms of final destination. This may lead to highly unfair delay for small block data. To mitigate this unfairness, relay nodes may mix only packets going to the same destination. We call this strategy FairMix. Although FairMix may limit the maximum attainable throughput, it aims to make distinct for decoding delay of each destination corresponding to the size of the data block. In order to investigate this trade off, we compare the FairMix performance with a naive network coding which mixes packets destined to different destinations. The simulation under lossy wireless links, limited memory and bandwidth resources, and different block sizes shows that FairMix is effective in improving fairness among destinations in comparison to naive network coding.

We consider multiple source asynchronous broadcasting problem. That is, in each broadcast, one of the nodes is the source, and the message is to be received, unaltered, by all the other nodes in the network. We propose to exploit LT code, which is one of the fountain codes, with the source independent backbone in order to reduce the number of transmissions for broadcasting with network coding in ad hoc wireless network. We use the principle of LT code to perform network coding in a simple distributed manner where encoding can be applied with both received singletons and non-singletons, and generated candidates can be used in an optimization criteria. We show by simulation that our approach reduces the number of transmissions required for flooding.

This paper presents an admission control algorithm based on dynamic constraints for multi-hop networks. Assuming each node knows the topology and flow reservations within its radio range, local constraints on flow rates can be computed. As long as these constraints are satisfied, flows are accepted. Since computing optimal constraints is not practical, existing approaches compute a system of either necessary or sufficient constraints. In practice, the approach based on necessary constraints tends to overload the network whereas in the latter approach, a significant part of the bandwidth remains unused. In addition, these works assume that the interference model and the sublayers are optimal. In this paper, we propose to take into account the channel state in the constraints computation and, thus, to adjust them according to model relevance. Therefore we give a probabilistic model to evaluate the time spent by the channel in the idle state. By comparing this estimation with the measure value, we evaluate the model accuracy and include the corresponding error rate in the constraints of the admission control. Simulations show that our admission control algorithm outperforms previous work.

An emerging approach for improving the performance of TCP in ad hoc multihop networks is to limit the maximum congestion window (CWNDmax) that a TCP connection is allowed to reach, in order to eliminate the number of outstanding segments and increase the TCP stability. In the present work, we propose an adaptive scheme to bound the CWNDmax value in an IEEE 802.11 ad hoc network. Our contributions are the following. First, we conduct simulation experiments to establish the argument that the optimum CWNDmax value depends on the buffer availability, when the network is not saturated, and is irrelevant to it, otherwise. Then, we introduce a time based expression for the network's bandwidth-delay product (BDP), in order to set CWNDmax dynamically. This expression accounts both for spatial reuse and for the packets' queue waiting time. The latter is necessary, since the TCP timer is set according to the round-trip delay, which includes the buffering latency in all hops. The proposed model can be implemented in a real environment, whereas the simulation experiments show that it improves the TCP window stability. The idea of limiting CWNDmax proves interesting, mainly because it aims to leave TCP unchanged.

The rapid proliferation of mobile devices has influenced the potential growth of wireless networking applications. This has lead to an augmentation in wireless ad hoc networking scenarios, particularly interesting for network operators. In this work, we present an adaptive framework for weight metric estimation and dissemination to construct stable and reliable weight-based clusters which can provide faster convergence rates and performance results for dynamic routing in mobile ad hoc networks. The framework considers critical node properties in determining a node's suitability for becoming clusterheads. It employs adaptive cluster radius and dynamic network constraints as the weight dissemination criterion. We observe that the proposed algorithm is suitable for scalable ad hoc networks and provides stable cluster formation decisions based on weighted metric approaches. Extensive performance evaluations confirm the suitability of the protocol for adaptive stable cluster formation and control overhead reduction in mobile ad hoc networks. We also provide comparisons with other clustering algorithms.

We present an optimized scalable simulation model for TCP, developed in OPNET, and investigate its performance in the case of OLSR mobile ad-hoc networks (MANETs). The key idea for the model's construction is to represent each node by a subqueue, in the simulation model. Thus, the exchange of packets in the network is literally a set of enqueue/dequeue operations among the subqueues. The physical, channel access, routing, and transport protocols' algorithms operate appropriately upon every such packet exchange, to simulate the different network levels. Such an approach for network modeling allows to reach very large simulation times, therefore letting the network reach its steady state and allowing to study the system's long-term performance. We apply this model to study the performance of TCP in MANETs, and the interactions among the involved protocols. Compared to the existing models, it is fully scalable and optimized, as shown by the simulation results.

In this paper, we study the scalability of OLSR (Optimized Link State Routing) protocol, adapted for Multi-hop Mobile Ad Hoc Networks. We present a modified OLSR routing protocol, G-OLSR (Grid-OLSR) which incorporates the advantages of topology-based and position-based routing. The protocol has been designed to serve easier and robust ad hoc network deployments interesting for network operators and service providers, supporting mission-critical applications and innovative services as well as for fully distributed scenarios interesting for spontaneous deployments and mesh-type wireless multi-hop networks. The simulation results corroborates that the proposed schemes performs better than the OLSR routing scheme and from the analyses, we could interpret that G-OLSR is more suited for scalable mobile ad hoc networks.

Ad hoc networks arouse imminently an important interest within industrial and research communities. Actually, their salient features, essentially the absence of infrastructure and auto-management, promise huge applications and possibilities for wireless communication. However, the tremendous boom of these networks depends incontestably on their reliability in terms of security and quality of services (QoS). In this paper, we study the ad hoc security vulnerabilities for which cryptographic-based solutions are ineffective and which require IDS. Appropriate designed IDS services appear essential as countermeasures to those threats, where previous IDS proposals often seem to be too sophisticated in the ad hoc environment and merely ineffective. Our goal here is to provide an IDS mechanism dedicated to the OLSR protocol, fitting to its characteristics and operation, and designed to avoid its vulnerabilities. Hence, our proposed IDS represents an urgent and primary line of defense since it protects from the protocol flaws themselves avoiding a significant panoply of easily operated attacks.

The rapid proliferation of wireless devices has lead to an augmentation in mobile ad hoc networking scenarios, particularly interesting for commercial applications and to network operators. Scalability of ad hoc networks, with respect to routing has been an important research issue recently. It is well known that clustering is the commonly agreed upon solution for efficient routing, topology management and resource utilization in a large scale mobile ad hoc network topology. This paper proposed a hybrid routing mechanism for cluster-based ad hoc networks, realized through a novel cluster-quality based routing approach. The main goal of our scheme, which employs a hybrid approach, is to guarantee efficient cluster-to-cluster routing by optimizing cluster-route selection. To achieve this, we introduce a new cluster-quality metric, which is an indirect quality-of-service metric that can estimate the current performance state of participating clusters. Since, traditional QoS metrics are hard to estimate in ad hoc networks and all the more challenging in a dynamic clustered network environment, the objective is to have a better adapted mechanism for providing guaranteed routing. The authors also present an optimization algorithm for intra-cluster routing and to reduce the cluster re-organization overhead. The proposed scheme is evaluated through simulations, and the results indicate that our protocol scales well with increasing node-count, node-density and node-speed. The effectiveness of the cluster-quality metric is also studied.

Mobile IP is used to keep track of location information and make the data available to the mobile device anytime, anywhere. It designed to address the macromobility management problem, it does not address microlevel mobility issues such as handoff latency and packet loss. In this paper, we propose a fast and efficient handoff scheme to handle the movements of mobile nodes among a different wireless network technologies. Our scheme combines: (a) A hierarchical mobility management architecture to hide mobility of mobile nodes within the foreign domain from the home agent, (b) The use of multicast as the packet forwarding mechanism from the getaway foreign agent to the base stations, (c) The use of our proposed virtual cells in order to reduce the upward vertical handoff latency and disruption as much as possible. Our design is based on the Internet protocol (IP) and is compatible with the mobile IP standard (MIP). We also present simulation results showing that our handoff scheme is very fast and avoid packet loss.

In full-IP networks, IP-based protocols are used for mobility management. Therefore, one of the most important issues is to design efficient IP-based mobility management schemes and evaluate their performance. In a recent work we proposed an integration of mobile-IP with OLSR, a routing protocol for ad-hoc networks, to manage universal mobility. In this paper we present the performance measurements of this implementation in the presence of both macro-mobility and micro-mobility. The measurements we obtained justify the choice of OLSK for managing micro-mobility and show the advantage of using multipoint relays to optimize flooding of mobile-IP Agent Advertisements in the ad-hoc network.

Mobile IP (and Ipv6) is used to keep track of location information and make the data available to the mobile device anytime, anywhere. It designed to address the macro mobility management, it does not address micro-level mobility issues such as handoff latency and packet loss. In this paper, we propose a mobility management scheme to handle the movements of mobile nodes among different wireless network technologies. Our scheme combines: (a) A hierarchical mobility management architecture to hide mobility of mobile nodes within the foreign domain from the home agent (b) The use of multicast as the packet forwarding mechanism from the gateway foreign agent to the base stations (c) A scheme for users with high-mobility/low-mobility to minimize packet loss (d) The use of forwarding pointers to help in providing efficient location management without informing the home agent. We also present simulation results showing that the loss rate can be minimized for faster moving mobiles. The case of a mobile changing speed is also addressed.

Future wireless systems will have to support multimedia services such as voice, video and data. Several mechanisms, like multiple access, bandwidth allocation and power control are used for providing these multimedia services. In the 3/sup rd/ generation of wireless systems, WCDMA is used for the access method in the FDD mode. Therefore, the capacity of the system is based on the cross correlation among the user's allocated scrambling codes. In this work, we analyze the WCDMA uplink resource allocation and propose a new method, called one service-one scrambling code (OSSC), that reduces the aggregate number of scrambling codes assigned to users in a cell. We also study the impact of the scrambling code assignment on the call interference and the system capacity. An analytical model is provided in this paper.

Current cellular systems suffer already from signaling that uses the air interface resource. For example, in GSM systems, half of the available resources is dedicated for common and dedicated signaling. For future generations, systems will propose more services with QoS requirements. This increases the quantity of control information on the radio interface. In this paper, we propose a mobile agent based framework in order to reduce the number of signaling requests between the terminal and its base station. A POP3 application was used to illustrate the performance of the framework.

This paper gives an overview of the French collaborative project SAMU, Advanced Services by Mastering UMTS, dedicated to developing enhanced services for users in a car. For that purpose, complementary research domains have been investigated such as radio resource management, IP over UMTS and the use of software agents. While field trials were planned in the project to validate the outputs of the abovementioned research areas over a UMTS experimental network, the general delay encountered by UMTS manufacturers led the project to investigate alternative experimentation. Hence, a UMTS-TDD software radio platform has been built to show IP based telematics applications over UMTS.

HTTP is already the most popular application on wired networks. With the arrival of the UMTS and its high data bit rate, the HTTP will become useful on portable computers. Other services are also offered by the UMTS. All these services increase the quantity of control information on the radio interface. Therefore, research work in this area should optimize the occupancy of the air interface introduced by this signaling information. For example, in GSM systems, half of the available resources is devoted to common and dedicated signaling. In this paper, we propose a mobile agent-based framework in order to reduce the number of signaling requests between the terminal and its base station. A Web access application is used to illustrate the performance of our framework.

Third generation wireless system is based on the CDMA access technique. In this technique, all users share the same bandwidth simultaneously but with different codes. This sharing generates interference that can reduce the system's capacity when using a weak code allocation algorithm. We analyze the WCDMA capacity as a function of the type and the number of allocated codes. We also study the method used to assign codes to the users. Finally we propose a new scheme that assigns the code allocation according to the type of user application. Simulation model and results are also provided.

Current cellular systems already suffer from signaling that uses the air interface resource. For example, in GSM systems, half of the available resources is dedicated for common and dedicated signaling. For future generations, systems should propose more services with QoS requirements. This must increase the quantity of control information on the radio interface. We use a mobile agents based framework that was proposed in a previous work for POP3 application and we introduce an optimization of the HTTP protocol for the air interface. The radio signaling and the adaptive degradation are also studied.

We present different aspects of quality of service that should be adapted to the BRAIN architecture. Several parameters and policies of QoS are depicted. Also, the paper shows the dynamic adaptation of these parameters in the context of BRAIN.

We analyze the possibility to apply the tree random access protocol (also called the stack protocol) for the W-CDMA part in the UTRA radio interface proposition. We study also a priority system applied on the random access directly. The analytical model uses generating functions and an algebraic method in order to show the stack protocol performance. Also, numerical and simulation results are presented and show the predominance of this protocol compared with the slotted ALOHA mechanism.

An integrated voice and data system using the channel segregation protocol (CS) is analyzed. To achieve each service target carrier to interference ratio (C/I), and meet the associated bit error rate (BER) requirements, the learning process inherent in the CS is extended by weighting the slot priorities, based on previous successful attempts, according to each service C/I requirement. Simulation results show an improvement in call block and achieved C/I levels for voice while the average delays for packet data are improved as well. The study is conducted for non real time packet data services exhibiting heavy tailed packet size distributions.