In this paper, we will propose a novel bandwidth allocation/sharing/extension (DBASE) protocol to support both asynchronous traffics and multimedia traffics with the characteristics of variable bit rate (VBR) and constant bit rate (CBR) over IEEE 802.11 ad hoc wireless local area networks. Overall quality of service (QoS) will be guaranteed by DBASE. The designed DBASE protocol will reserve ban...

Peak and volume of river flows are functions of the catchment surface characteristics. This means that any impacts to the run-off regime (for example surface sealing and river training) could affect people and land users in the lower system. The costs of flood defence or compensation of damages are usually not included in the economic calculation of the upstream land owner or land user. In econ...

Certificate revocation is an important security component in mobile ad hoc networks (MANET). Securing network from various kinds of Attacks (MANET) plays an important role. Certificate revocation mechanisms play an important role in securing a network. The main challenge of certificate revocation is to revoke certificates of malicious nodes promptly and accurately. In this paper we use Cluster ...

We consider a two-priority queueing system which represents an ATM node serving both variable bit rate (VBR) and unspeciied bit rate (UBR) traac. We determine the (transmission or link) capacity necessary for each traac type to guarantee prespeciied quality of service (QoS) requirements. This is done by means of a steady state performance analysis of the tail distribution of the buuer occupanci...

Media data are VBR in nature due to the coding and compression technologies applied. As VBR streams are complicated for network management, different approaches were proposed to shape the VBR stream as a transmission schedule with smoothed traffic burst. In this paper, instead of giving a fixed schedule result, a novel traffic shaping scheme is proposed to decide a schedulable region for all op...

In order to achieve acceptable service quality, the broad spectrum of Internet services requires differentiated handling and forwarding of the respective traffic flows within increasingly “Internet Protocol (IP)” based mobile networks. The “3rd Generation Partnership Project (3GPP)” standard based procedures allow for such service differentiation by means of dedicated “GPRS Tunnelling Protocol ...

The Connection Oriented Data Service (CO service) has been defined by the IEEE 802.6 committee to support variable-bit-rate (VBR) data services over DQDB MANs. The main aim of the CO service is to be able to guarantee the QoS required by a wide variety of VBR services. In this paper, we derive an adaptive bandwidth allocation control mechanism for the DQDB CO Data service. Numerical results dem...

A network that ooers deterministic, i.e., worst-case, quality-of-service (QoS) guarantees to variable-bit-rate (VBR) video must provide a resource reservation mechanism that allocates bandwidth, buuer space, and other resources for each video connection. Such a resource reservation scheme must be carefully designed, otherwise network resources are wasted. A key issue for the design of a resourc...

The bit rate variability of video streams is a diicult obstacle to make an eecient VOD server. It is a nuisance especially for deterministic systems, where resources are reserved to guarantee quality of service. We propose a novel way to deal with it, tip prefetching. Its main idea is prefetching parts of largest blocks in the buuer, leveling the amount of data being read from disks in each rou...