<p>Performance is the driving force for the effective network utilization in the current telecommunication world. The thesis aims to define suitable performance measurement methodologies for communication over stack based Signalling System No 7 (SS7). This thesis also throws a quick glance on open source SS7 and Ericsson proprietary SS7 protocols, to devise performance measurement approach that can be adopted to develop sophisticated tools. We adopt a scientific experimental approach for numerical measurement of throughput and latency of the protocol stack. Our current work finishes experimentation with open source SS7 protocol (SCTP) in Fedora based two identical servers. SCTP (Stream Control Transmission Protocol) is an important transport layer protocol for communication of SS7 message over an IP network. Message communication using SCTP protocol over an IP/Ethernet network between these two identical servers has been measured and analyzed using the IPerf tool. TCP (Transmission Control Protocol) being another important transport layer protocol of TCP/IP stack, the performance of TCP is compared with SCTP. The results prove that under normal circumstances TCP gains over SCTP and our analysis support that under multi homing support, SCTP should gain over TCP when throughput is measured</p>

<p>Companies and authorities of today often handle large amount of data, not unusually with a restricted content which should be kept secret from outsiders. One way of accomplish this is to encrypt stored data in real time. For this a hardware solution is ideal since it can be independent, fast enough, and easily added to already existing systems.</p><p>This report is a starting point to achieve this with two of the most common mass storage standards SATA and SCSI in focus. It is based on the task to develop a FPGA based SATA controller and investigate the possibility to ”speak” SCSI with SATA devices.</p><p>The working process has involved theoretical studies, system design, test driven development using simulations and hardware tests and technical investigation.</p><p>The thesis resulted in a SCSI-to-SATA translation investigation pointing out difficulties and presenting a translation model. A SATA host was also implemented in VHDL on a Virtex-5 FPGA that can execute a number of SATA commands on different devices. Simulations performed shows that the total latency reaches one <em>μ</em>s/32 bits in the SATA host and that should not be much of a problem for most applications in a possible bridge solution. </p>

<p>Wireless sensor networks offer easy implementation, flexibility and mobility of hand held </p><p>devices. Sensors consist of an internal power source, which is the great limitation for </p><p>the life time and the usage of sensor networks. To increase the life time, sensors should </p><p>stay in energy saving sleep mode as long as possible, because in sleep mode the radio is </p><p>either shut down or working with less energy. Better energy handling is implemented in </p><p>different power saving mechanism of common Medium Access Control protocols, which are </p><p>evaluated and analyzed and further extensions and ideas to improve the energy efficiency </p><p>are presented. Slotted PSM is simulated with the NS2 and compared to the WLAN 802.11 </p><p>PSM technology and the results show that energy efficiency and power consumption are </p><p>much better implemented and life time increases with the use of Slotted PSM.</p>

<p>In the last decade, we have seen an explosive growth in the deployment of multimedia applications on the Internet. However, the transport service provided over the Internet is not always feasible for these applications, since the network was originally designed for other types of applications. One way to better accommodate the service requirements of some of these applications is to provide a partially reliable transport service. A partially reliable transport service does not insist on recovering all, but just some of the packet losses, thus providing a lower transport delay than a reliable transport service. The work in this thesis focuses on the design, implementation, and evaluation of a partially reliable transport protocol called PRTP. PRTP has been designed as an extension to TCP in order to show that such a service could be effectively integrated with current protocol standards. An important feature of PRTP is that all modifications for PRTP are restricted to the receiver side, which means that it could be very easily deployed. The thesis presents performance results from various experiments on a Linux implementation of PRTP. The results suggest that transfer times can be decreased significantly when using PRTP as opposed to TCP in networks in which packet loss occurs. Furthermore, the thesis includes a study that investigates how users perceive an application that is based on a partially reliable service. Specifically, how users select the trade-off between image quality and latency when they download Web pages is explored. The results indicate that many of the users in the study could accept less than perfect image quality</p><p>if the latency could be shortened.</p>

The IEEE 802.11a has become the mainstream protocol used in modern wireless communication system due to its high propagation rate of data (54 Mb/s). To meet high propagation rates, the communication devices used in IEEE 802.11a protocol usually present a high conversion gain and a high linearity (denoted as third order intercept point, IIP3). The IIP3 of conventional up- and down-conversion mixers are only about 0 dBm and -5 dBm, which fail to achieve a high propagation rate of data. This thesis utilizes the TSMC 0.18 &#x00B5;m CMOS technology to design and fabrication up- and down-conversion mixers with very high linearity for IEEE 802.11a application. The proposed high-linearity up-conversion mixer with 1.01 mm ¡Ñ 0.85 mm chip size and its wide bandwidth (5~6 GHz) is well suited for IEEE 802.11a application. To enhance the linearity and bandwidth, a transconductor stage with gm-boosted structure, a switch stgae with LO-body grounded structure and a load stage with shunt peaking structure are adopted in this research. Under 5.2/5.4/5.8 GHz operating frequencies, the implemented up-conversion mixer demonstrates a high conversion gain of 6.8/7.1/6.3 dB and a high linearity of 8.9/9/13.2 dBm, respectivly. In addition, a moderate consuming power (6.86 mW) of such mixer can be achieved at 1.2 V supply voltage. On the other hand, this thesis also designed and fabricated a high-linearity down-conversion mixer with chip size of 1.02 mm ¡Ñ 0.86 mm and 5.2 GHz center frequency. To improve the linearity and isolation and reduce the high-order noise, a transconductor stage with dual-gate structure and a load stage with RC-tank structure are adopted in this research. According to the EM-simulation resutls, the proposed down-conversion mixer presents a moderate conversion gain of 6 dB and a high linearity of 0.8 dBm. Additionly, a moderate consuming power (6.75 mW) of such mixer can be achieved at 1.8 V supply voltage.

Security has become one of the major concerns in the Intelligent Transportation Systems (ITS). The Trusted Truck(R) System, provides an efficient wireless communication mechanism for safe exchange of messages between the moving vehicles (trucks) and the roadside inspection stations. The vehicles and the station are equipped with processing units but with different computational capabilities. To make this Trusted Truck(R) system more secure, this thesis proposes a secured data protocol which ensures data integrity, message authentication and non-repudiation. The uniqueness of the protocol is: it is cost-effective, resource-efficient and embeds itself into the Trusted Truck (R) environment without demanding any additional infrastructure. The protocol also balances the computational load between the vehicle and station by incorporating an innovative key transport mechanism. Digital signatures and encryption techniques are used for authentication and data con dentiality. Cryptography algorithms along with optimization methods are used for the digital signatures. The computational time for the algorithms are analyzed. Combining all these techniques, an efficient secured data protocol is developed and implemented successfully.

No description available.

Mobile communication systems are experiencing a huge growth. While traditional communication paradigms deal with fixed networks, mobility raises a new set of questions, techniques, and solutions. This work focuses on wireless sensor networks (WSNs) where each node is a mobile device. The main objectives of this thesis have been to develop algorithms and protocols enabling WSNs with a special interest in overcoming mobility support limitations of standards such as Bluetooth and Zigbee. The contributions of this work may be divided in four major parts related to mobility support. The first part describes the implementation of local positioning services in Bluetooth since local positioning is not supported in Bluetooth v1.1. The obtained results are used in later implemented handover algorithms in terms of deciding when to perform the handover. Moreover local positioning information may be used in further developed routing protocols. The second part deals with handover as a solution to overcome the getting out of range problem. Algorithms for handover have been implemented enabling mobility in Bluetooth infrastructure networks. The principal achievement in this part is the significant reduction of handover latency since sensor cost and quality of service are directly affected by this parameter. The third part solves the routing problems originated with handovers. The main contribution of this part is the impact of the Bluetooth scatternet formation and routing protocols, for multi-hop data transmissions, in the system quality of service. The final part is a comparison between Bluetooth and Zigbee in terms of mobility support. The main outcome of this comparison resides on the conclusions, which can be used as a technology election guide. The main scientific contribution relies on the implementation of a mobile WSN with Bluetooth v1.1 inside the scope of the ”Multi Monitoring Medical Chip (M3C) for Homecare Applications” European Union project (Sixth Framework Program (FP6) Reference: 508291) offering multi-hop routing support and improvements in handover latencies with aid of local positioning services.

Syfte: Studiens syfte var att jämföra en ny extubationsalgoritm med sedvanligtextubationsförfarande. Gruppen som studerades var patienter som genomgått en HIPEC-operationoch vårdats på Centrala intensivvårdsavdelningen. Metod: I En randomiserad kontrollerad klinisk pilotstudie randomiserades patienterna till en av tvågrupper. Därefter extuberades patienten enligt en studiealgoritm eller post-operativ standard. Resultat: Syresättningen var väsentligen oförändrad för studiegruppen (37,5 kPa till 36,6 kPa)medan den sjönk för kontrollgruppen (50,1 kPa till 40,6 kPa) vid jämförelse mellan 10 minuter efterankomst och 15 minuter efter extubation. Efter 13 till 18 timmars kontroll strax innan patienternalämnade intensivvårdsavdelningen var syresättningen på samma nivå som 15 minuter efterextubation för både studiegruppen och kontrollgrupp. Således kvarstod en försämrad syresättninghos kontrollgruppen vid utskrivning jämfört med 10 minuter efter ankomst. Slutsats: Studien visar att det skulle kunna vara fördelaktigt att extubera patienter enligt denstudiealgoritm som testats jämfört med dagens kliniska standard. Genom att fokusera på hur och ejnär extubationen ska ske är förhoppningen att denna studie kan bidra till att förbättra en procedursom i princip saknar konsensus. Mer forskning krävs för att kunna dra några generella slutsatser omresultatet. / Aim: To compare a new method of extubation with present standard procedure at the Central ICUafter HIPEC surgery. Method: In a randomized controlled study patients were randomized into two groups. Patients wereeither extubated according to a study algorithm based on best current knowledge, or according tostandard procedure. Results: The oxygenation remained on the same level in the study group (37,5 kPa to 36,6 kPa) butdecreased in the control group from 50,1 kPa to 40,6 kPa from 10 minutes after arrival to 15minutes after extubation. After 13 to 18 hours, just before the discharge from the ICU theoxygenation in both groups was at the same level as 15 minutes after extubation. Thus a decrease inoxygenation in the control group was found at discharge compared to 10 minutes after arrival in theICU. Conclusion: The result of the study showed that it may be benificial to extubate according to thestudy algorithm compared to present standard procedure. By directing focus from when to how theextubation is made, this study may contribute to the improvement of a clinical procedure that iscurrently lacking in scientific consencus. Further studies are needed to confirm these findings.

The aim of this thesis is to study China's position regarding the global climate and the numerous topics discussed in the global meetings held during 1997, ending in the Kyoto summit in the same year. Chinas position during this year was evidently on the side of developing countries. China regarded topics such as technology transfer, emission trading and Commitments for the participating parties as very important topics which had to be considered. Chinas final position regarding these subjects was during 1997: - Increased funding and technology transfer resources to developing countries. - Objection to the inclusion of emission trading in the protocol. - No new commitments of any nature for developing countries. - National development is Chinas key issue.