Dynamic Secure-Aware Real Time Scheduling Algorithm for Packet Switched Network

Now a day wireless networks are mostly preferred over wired networks because wireless networks are flexible and required no wire. If we talk about successful communication then end to end delivery of message is very important. In a heavy loaded networks scheduling of packets are key, by the proper scheduling of packets we can improve the guarantee ratio hence overall performance of the network is improved. If we focus on real time communication then real time packet scheduling plays an important role for enhance the performance of the system. In any network security plays a vital role, to protect the data from intruder and many security threats proper security of data is very important. So we can say that overall performance of the system is a combination of security and scheduling. In this paper we talk about real time packet scheduling in wireless networks. Here we use Dynamic Secure-Aware Real-Time Scheduling Algorithm for Packet Switched Network [DSASA]. This is a dynamic real time packet scheduling technique which reduce packets drop, increase guarantee ratio of data traffic and provide security for data packets

Providing Security to Wireless Packet Networks by using Optimized Security Method

Now-a-days technology is growing very fast, due to rapid development of the technology in computer arena, communication through network become a habit to the users. Communication through network is happen using two channels i.e., by connection oriented and connection less. At present users prefer wireless networks for communication and transferring data due to its flexibility. So in this paper we are focusing on wireless networking, as it is not reliable we are proposing an optimized security technique to provide security to the communication on wireless. In this paper we mainly focus on packet scheduling which plays the vital role in the transmission of data over wireless networks. We are using optimized security technique to secure the packets at initial level itself while scheduling the packets. Keywords: Real-Time Packets, Packet Scheduling, Wireless Networks, Security, Cryptography, Secret key, Bandwidth

Scheduling of real-time traffic in IEEE 802.11 networks

Real-time applications require the provision of time-bounded services from the network, however, the scheduling algorithms used in wired networks are not suitable for wireless networks because they assume that the channel is error free. Besides, the scheduler has only a limited knowledge of the arrival processes of the uplink traffic. In this paper, we propose scheduling algorithms for the transport of real-time traffic in IEEE 802.11 wireless LANs which deal with channel errors. We also present the simulation results obtained with these algorithms

Fast retransmission of real-time traffic in HIPERLAN/2 systems

Automatic repeat request (ARQ) schemes are effective to recover non-real-time data corrupted by channel errors, but their use with real-time traffic is seldom considered because packet retransmissions tend to increase the delay beyond the deadline. However, the high-speed of modern wireless local area networks, together with their inherent low propagation times, favors the use of ARQ schemes with real-time traffic. This paper proposes a fast retransmission scheduling mechanism for reliable transport of real-time traffic in HIPERLAN/2 systems, as well as an adaptive rate scheme designed to reduce the delay introduced by retransmissions while keeping the same level of network efficiency. The achieved performance is evaluated in the scenario of a distributed data acquisition and control system

Gestión distribuida con calidad de servicio garantizada para sistemas de transmisión por paquetes en entornos CDMA

En esta comunicación se presenta una estrategia de gestión distribuida para poder garantizar una cierta calidad de servicio en conexiones cuya transmisión se realiza en modo paquete. El entorno de trabajo son los sistemas de comunicaciones móviles multimedia con acceso múltiple CDMA. El esquema global se basa en un protocolo de acceso al medio del tipo DQRAP/CDMA y en una gestión de recursos basada a su vez en un criterio de Crédito pendiente de Servicio y un mecanismo de prioridades por servicio. Se muestra el modelo del sistema y los resultados obtenidos mediante simulaciones por ordenador de cara a validar el esquema propuesto.Peer ReviewedPostprint (author’s final draft

Cross layer design for service differentiation in mobile ad hoc networks

Cross layer design is a promising approach in mobile ad hoc networks (MANET) to combat the fast time-varying characteristics of wireless links, network topology, and application traffic. In this paper, we employ cross layer design to develop a novel scheduling scheme with two optimizations aimed at service differentiation. The scheduling scheme is executed at the network layer of every station according to the channel conditions estimated by the MAC layer. The optimizations are based on traffic property sharing and packet timeout period interaction to reduce the packet collisions and improve network performance. We evaluate the proposed scheme under different network loads in terms of packet delivery ratio, average end-to-end delay and delay jitter. The simulation results show that our scheme can provide different service differentiations for time-bounded and best effort traffics. In particular, we can guarantee the delay and delay jitter requirements of time-bounded traffic. © 2003 IEEE.published_or_final_versio

On channel-adaptive fair multiple access control

Multiple access control (MAC) of the uplink in a wireless mobile computing system is one of the most important resource allocation problems in that the response time and throughput of user applications (e.g., wireless Web surfing) are critically affected by the efficiency of the MAC protocol. Compared with a traditional MAC problem (e.g., the wireline Ethernet), there are two important new challenges in a modern wireless network: (1) multimedia data with diverse traffic requirements are involved; and (2) the wireless channel has a time-varying quality for each user. Furthermore, a more prominent user requirement is fairness among different users, possibly with different traffic demands. While some protocols have been suggested to handle multimedia data and/or tackling the time-varying channel, there are a number of drawbacks in these existing protocols. The most notable drawback is that the channel model is rather unrealistic - just using a two state Markov chain instead of relying on accurate models of multipath fading and shadowing effects. Another common deficiency is that fairness is ignored. In this paper, we propose to use a new notion of fairness that can capture a realistic channel model, and to integrate a fair queueing scheduling algorithm in a MAC protocol to optimize performance while maintaing fairness among users regardless of their channel states and data types.published_or_final_versio

CPLD-PGPS scheduling algorithm in wireless OFDM systems

In this paper, we propose a new scheduler for orthogonal frequency-division multiplexing (OFDM) wireless communication systems, called Channel-Condition and Packet-Length Dependent Packet Generalized Processor Sharing (CPLD-PGPS) scheduler. CPLD scheduler considers the condition of the physical channel and the length of packets at the same time, and optimally allocates the sub-carriers in a frame. With this scheduler, the system can achieve better system BER performance, and correspondingly superior PER performance. The system throughput is improved, at the same time the required bandwidth is guaranteed, and long term fairness for all the traffic in the system is provided. In order to reduce the algorithm complexity, a simplified CPLD is proposed, which maintains the system throughput as in the original scheduler, and guarantees the system performance with properly set system parameters. The superior performance of the proposed scheduler is demonstrated by simulation results. © 2004 IEEE.published_or_final_versio