5,266 research outputs found
Performance of TCP over UMTS common and dedicated channels
Universal Mobile Telecommunications System (UMTS) is a third-generation cellular network that enables high-speed wireless Internet access. This paper investigates the performance of Transmission Control Protocol (TCP) over UMTS utilizing a common and four dedicated transport channels with bit rates up to 2 Mb/s. The performance of TCP was examined under varying channel conditions. Bulk data transfer and interactive traffic was considered in the simulation. The simulation results show that the behaviour of TCP is closely coupled to the UMTS radio link control layer. A maximum TCP throughput is achievable for transport channels with bit rates up to 384 kb/s. The gain in request-response time for interactive traffic is relatively small for high bit rate channels because the UMTS radio interface is latency limited for small object sizes
The MobyDick Project: A Mobile Heterogeneous All-IP Architecture
Proceedings of Advanced Technologies, Applications and Market Strategies for 3G (ATAMS 2001). Cracow, Poland: 17-20 June, 2001.This paper presents the current stage of an IP-based architecture for heterogeneous environments, covering UMTS-like W-CDMA wireless access technology, wireless and wired LANs, that is being developed under the aegis of the IST Moby Dick project. This architecture treats all transmission capabilities as basic physical and data-link layers, and attempts to replace all higher-level tasks by IP-based strategies.
The proposed architecture incorporates aspects of mobile-IPv6, fast handover, AAA-control, and Quality of Service. The architecture allows for an optimised control on the radio link layer resources. The Moby dick architecture is currently under refinement for implementation on field trials. The services planned for trials are data transfer and voice-over-IP.Publicad
Resource management in IP-based radio access networks
IP is being considered to be used in the Radio Access Network (RAN) of UMTS. It is of paramount importance to be able to provide good QoS guarantees to real time services in such an IP-based RAN. QoS in IP networks is most efficiently provided with Differentiated services (Diffserv). However, currently Diffserv mainly specifies Per Hop Behaviors (PHB). Proper mechanisms for admission control and resource reservation have not yet been defined. A new resource management concept in the IP-based RAN is needed to offer QoS guarantees to real time services. We investigate the current Diffserv mechanisms and contribute to development of a new resource management protocol. We focus on the load control algorithm [9], which is an attempt to solve the problem of admission control and resource reservation in IP-based networks. In this document we present some load control issues and propose to enhance the load control protocol with the Measurement Based Admission Control (MBAC) concept. With this enhancement the traffic load in the IP-based RAN can be estimated, since the ingress router in the network path can be notified by marking packets with the resource state information. With this knowledge, the ingress router can perform admission control to keep the IP-based RAN stable with a high utilization even in overload situations
Transmission Delay of Multi-hop Heterogeneous Networks for Medical Applications
Nowadays, with increase in ageing population, Health care market keeps
growing. There is a need for monitoring of Health issues. Body Area Network
consists of wireless sensors attached on or inside human body for monitoring
vital Health related problems e.g, Electro Cardiogram (ECG),
ElectroEncephalogram (EEG), ElectronyStagmography(ENG) etc. Data is recorded by
sensors and is sent towards Health care center. Due to life threatening
situations, timely sending of data is essential. For data to reach Health care
center, there must be a proper way of sending data through reliable connection
and with minimum delay. In this paper transmission delay of different paths,
through which data is sent from sensor to Health care center over heterogeneous
multi-hop wireless channel is analyzed. Data of medical related diseases is
sent through three different paths. In all three paths, data from sensors first
reaches ZigBee, which is the common link in all three paths. After ZigBee there
are three available networks, through which data is sent. Wireless Local Area
Network (WLAN), Worldwide Interoperability for Microwave Access (WiMAX),
Universal Mobile Telecommunication System (UMTS) are connected with ZigBee.
Each network (WLAN, WiMAX, UMTS) is setup according to environmental
conditions, suitability of device and availability of structure for that
device. Data from these networks is sent to IP-Cloud, which is further
connected to Health care center. Main aim of this paper is to calculate delay
of each link in each path over multihop wireless channel.Comment: BioSPAN with 7th IEEE International Conference on Broadband and
Wireless Computing, Communication and Applications (BWCCA 2012), Victoria,
Canada, 201
- âŠ