The fast growth of Internet traffic, the growing importance of cellular accesses and the escalating competition between content providers and network operators result in a growing interest in improving network performance and user experience. In terms of network transport, different solutions ranging from tuning TCP to installing middleboxes are applied. It turns out, however, that the practical results sometimes are disappointing and we believe that poor testing is one of the reasons for this. Indeed, many cases in the literature limit testing to the simple and rare use case of a single file download, while common and complex use cases like web browsing often are ignored or modelled only by considering smaller files. To facilitate better testing, we present a broader view which includes domain counts, flow counts and different forms of concurrency to better characterise the complexity around web pages, and from which the potential for different optimisation techniques can be estimated. We also derive numerical values of these metrics for a small set of popular web pages and study similarities and differences between pages with the same kind of content (newspapers, e-commerce and video) and between pages designed for the same platform (computer and smartphone).
A body sensor network (BSN) is typically a wearable wireless sensor network. Security protection is critical to BSNs, since they collect sensitive personal information. Generally speaking, security protection of BSN relies on identity (ID) and key distribution protocols. Most existing protocols are designed to run in general wireless sensor networks, and are not suitable for BSNs. After carefully examining the characteristics of BSNs, the authors propose human interactive empirical channel-based security protocols, which include an elliptic curve Diffie–Hellman version of symmetric hash commitment before knowledge protocol and an elliptic curve Diffie–Hellman version of hash commitment before knowledge protocol. Using these protocols, dynamically distributing keys and IDs become possible. As opposite to present solutions, these protocols do not need any pre-deployment of keys or secrets. Therefore compromised and expired keys or IDs can be easily changed. These protocols exploit human users as temporary trusted third parties. The authors, thus, show that the human interactive channels can help them to design secure BSNs.
Identity based infrastructure allows the public keyof a user to be derived easily from a predefined aspect of theirknown identity such as a phone number, passport number orother universally unique identifier. Recently, H¨olbl and Welzerhave proposed an identity-based key establishment protocol.However, this protocol is found to be vulnerable to man-inthe-middle attacks and impersonation attacks. In this paper,we propose multi-channel identity based protocols for wirelesspersonal area networks which can eliminate these attacks.These protocols alleviate the certificate overhead by using apublic key infrastructure which is suitable for wireless personalarea networks.
Internet of Things facilitates interaction betweenhuman users and physical environment through the use ofelectronic sensors, wireless communication and cloudtechnology. In this paper, we demonstrate a scalableimplementation of Internet of Things in a lab environment. Aversatile set of sensors including cameras, power outlets andordinary temperature sensors are embedded in the physicalenvironment and connected to the cloud via local gateways. Datais processed locally and accessible via the cloud. A web servicehosted in the cloud enables remote two-way interaction betweenthe human users and the monitored physical environments.
Research seminar, as a teaching form, is excellent in helping students achieve active learning. This work presents the author's experience on the using of research seminars at Kristianstad University.
The broadcast nature of wireless communication makes it intrinsically vulnerable to eavesdropping attacks. This article suggests the using of secret spreading codes (i.e. only a legitimate receiver knows the spreading sequence) and artificial interference (i.e. by intentionally adding noise to the broadcast channel) on countering eavesdropping attacks. We have made a theoretical analysis on the potential performance degradation at the eavesdropper and at the legitimate receiver for a point-to-point wireless communication system using direct-sequence spread spectrum (DSSS) with coherent phase-shift keying (PSK) modulation. We have also proposed a lightweight non-cryptographic secret code generation scheme which leads to low correlation between the spreading codes used at the transmitter and at the eavesdropper. Simulation results confirms the good anti-eavesdropping performance on using the proposed non-cryptographic secret code generation scheme. Simulation results also conform with the theoretical analysis and motivate the using of artificial interference on countering eavesdropping attacks.
Kvalitetssäkring är ganska viktigt i högre utbildning. Som den sista kursen i ett utbildningsprogram, självständig examensarbete har en tung roll. I de flesta lärosäten, har ett examensarbete en handledare och en examinator. Examinatorn bestämmer vilket betyg ett arbete ska få eller om det ska bli underkänd. Jag har upptäckt två problem i systemet: 1. Bedömning från en individuell examinator är subjektiv och detta har flera konsekvenser, bl.a. icke-förtroendefulla relationer mellan lärare och elev, orättvisa för studenter, och även ojämna kvalité hos universiteten och högskolor; 2. Handledare och examinatorer får en schablon resurstilldelning för varje student och faktiskt blir straffad när en student blir underkänd.
Medan det första problemet är en allmän fråga, det andra kan vara ett specialfall för oss. Båda problemen undergräver kvalitetssäkringssystemet. Diskussioner här gäller att hitta en lösning till problemen. Bland annat, peer-review, grupp examinering, och arbetsbelastning baserad resursfördelning ska diskuteras.
Internet of Things is evolving from the theory into reality. It is increasingly embedded into our daily lives to provide critical services such as pervasive healthcare and intelligent transportation systems, for which our privacy and security highly rely on the proper functioning of the products. This paper proposes a lightweight session-key establishment protocol that provides fundamental protection for the sensitive information flow in the Internet of Things. The new session-key establishment scheme utilizes the fact that time synchronization is a standard service in most of the Internet of Things products, and relies on loose time synchronization information to achieve secure and fast key agreement. Compared to traditional session-key establishment methods such as the one used by Wi-Fi, the new scheme is more lightweight and also allows a faster session establishment which can be critical for real-time services.
The broadcast nature of wireless communication make it intrinsically vulnerable to jamming and eavesdropping attacks. Spread-spectrum techniques spread narrowband signals over a wide bandwidth, and provide good resistance to noise and jamming attacks. However, spread-spectrum signals can still be intercepted if their used spreading codes are known. To tackle this issue, this paper proposes a lightweight design on generating secret spreading codes. A secret spreading code has all the desired properties of an ordinary spreading code, plus its unpredictability. Our method on generating secret spreading codes is shown to be resistant to cryptanalysis, and has little requirement on memory and computing resources.
There is currently an ongoing digital transformation for sewage and wastewater management. By automating data collection and enabling remote monitoring, we will not only be able to save abundant human resources but also enabling predictive maintenance which is based on big data analytics. This paper presents a smart sewage water management system which is currently under development in southern Sweden. Real-time data can be collected from over 500 sensors which have already been partially deployed. Preliminary data analysis shows that we can build statistical data models for ground water, rainfall, and sewage water flows, and use those models for data forecast and anomaly detection.
Low data rate wireless networks can be deployed for physical intrusion detection and localization purposes. The intrusion of a physical object (or human) will disrupt the radio frequency magnetic field, and can be detected by observing the change of radio attenuation. This gives the basis for the radio tomographic imaging technology which has been recently developed for passively monitoring and tracking objects. Due to noise and the lack of knowledge about the number and the sizes of intruding objects, multi-object intrusion detection and localization is a challenging issue. This article proposes an extended VB-GMM (i.e. variational Bayesian Gaussian mixture model) algorithm in treating this problem. The extended VBGMM algorithm applies a Gaussian mixture model to model the changed radio attenuation in a monitored field due to the intrusion of an unknown number of objects, and uses a modified version of the variational Bayesian approach for model estimation. Real world data from both outdoor and indoor experiments (using the radio tomographic imaging technology) have been used to verify the high accuracy and the robustness of the proposed multi-object localization algorithm.
In this paper, we discuss fault diagnosis for wireless sensor systems. Fault diagnosis is only possible if comprehensive system monitoring is in place. We thus also present architecture for in-depth system monitoring.