Extremely low profile flexible antenna for medical body area networks

Medical Body Area Networks (MBAN) are widely used in healthcare systems employing in- and on-body applications. An extremely low profile patch antenna for the MBANs is presented in this paper. The antenna consists of two flexible printed circuit boards (FPCB) separated by an air gap and uses a rectangular radiating patch with four slots. Two variants of the antenna having single and dual band operation are discussed. The single band antenna operates at 2.4 GHz while the dual band antenna works at frequencies of 2.4 GHz and 4.3 GHz. Both versions of the proposed antenna offer good bandwidth, high gain and radiation coverage for the MBAN applications

Design of a compact multiband circularly polarized antenna for global navigation satellite systems and 5G/B5G applications

Design of a multiband circularly polarized antenna is proposed in this article. The antenna has a simple and compact form factor by employing single‐feed stacked patch structure. It exhibits good performance at the global navigation satellite system (GNSS) frequency bands of L1, L2, and L5 and cellular communications frequency band of 2.3 GHz. The antenna has a 3‐dB axial ratio bandwidth of 1.1%, 1.0%, 4.1%, and 1.5% at the four operating bands of L1 (1.575 GHz), L2 (1.227 GHz), L5 (1.176 GHz), and 2.3 GHz. The antenna also achieves a gain of more than 2.2 dBiC and efficiency of more than 70% at the four frequencies. A detailed parametric study is carried out to investigate the importance of different structural elements on the antenna performance. Results are verified through close agreement of simulations and experimental measurements of the fabricated prototype. Good impedance matching, axial ratio bandwidth, and radiation characteristics at the four operating bands along with small profile and mechanically stable structure make this antenna a good candidate for current and future GNSS devices, mobile terminals, and small satellites for 5G/Beyond 5G (5G/B5G) applications

A secure MAC protocol for Cognitive Radio Networks (SMCRN)

In addition to standard authentication and data confidentiality requirements, Cognitive Radio Networks (CRNs) face distinct security issues such as primary user emulation and spectrum management attacks. A compromise of these will result in a denial of service, eavesdropping, forgery, or replay attack. These attacks must be considered while designing a secure media access control (MAC) protocol for CR networks. This paper presents a novel secure CR MAC protocol: the presented protocol is analysed for these security measures using formal logic methods such as Burrows-Abadi-Needham (BAN) logic. It is shown that the proposed protocol functions effectively to provide strong authentication and detection against malicious users leading to subsequent secure communication

Flexible Ultra-Wideband Antenna for 5G and Beyond Wearable Applications

Millimeter wave frequencies are front running contenders for 5G wireless communications. A wideband antenna that can provide coverage in whole of these frequencies is a well sought off challenge. This paper presents design of a quasi-Yagi antenna consisting of three driven arms and three pairs of spiral directors that efficiently meets this requirement. To satisfy the flexibility demand of wearable applications, the antenna employs liquid crystal polymer LCP as the substrate. The antenna has a small size of 5×8×0.202 mm 3 while covering 24-71 GHz band.The proposed antenna achieves peak gain of 2.85, 6.33 and 8.52 dBi, respectively, and an efficiency of more than 70% in the desired frequency bands. The symmetric structure of the antenna also makes the fabrication easier. The ultra-wideband, radiation characteristics and flexibility of usage makes it a promising candidate for 5G and Beyond wearable applications

Prevention against threats to self co-existence - a novel authentication protocol for cognitive radio networks

Cognitive radio networks are intelligent networks that can sense the environment and adapt the communication parameters accordingly. These networks find their applications in co-existence of different wireless networks, interference mitigation, and dynamic spectrum access. Unlike traditional wireless networks, cognitive radio networks additionally have their own set of unique security threats and challenges, such as selfish misbehaviours, self-coexistence, license user emulation and attacks on spectrum managers; accordingly the security protocols developed for these networks must have abilities to counter these attacks. This paper presents a novel cognitive authentication protocol, called CoG-Auth, aimed to provide security in cognitive radio networks against threats to self co-existence. CoG-Auth does not require presence of any resource enriched base stations or centralised certification authorities, thus enabling it to be applicable to both infrastructure and ad hoc cognitive radio networks. The CoG-Auth design employs key hierarchy; such as temporary keys, partial keys and session keys to fulfil the fundamental requirements of security. CoG-Auth is compared with IEEE 802.16e standard PKMv2 for performance analysis; it is shown that CoG-Auth is secure, more efficient, less computational intensive, and performs better in terms of authentication time, successful authentication and transmission rate

A wearable antenna for mmWave IoT applications

A compact and flexible millimeter-wave (mmWave) antenna with central resonance frequency of 60 GHz has been designed. The performance of the antenna is evaluated numerically. The antenna exhibits a broad bandwidth of 9.8 GHz with a gain of 9.6 dBi. The antenna also provides good radiation coverage throughout the band of interest achieving a maximum efficiency of 70%. Simple structure, flexible geometry, ease of fabrication and excellent performance make it a well- suited option for body-centric IoT applications

Keyless security in wireless networks

Security in mobile wireless networks is difficult to achieve because of vulnerability of the links, inadequate physical protection, dynamically changing topology and the sporadic nature of the connectivity. The change in topology results in the change of trust relationships among the communicating nodes and as a consequence any security solution with a static configuration will not suffice. Key management and related protocols play a vital role and are the basis of security in many distributed systems. Cryptographic keys require dedicated mechanisms in place for their exchange before substantial security can be achieved; subsequently this exchange results in additional overhead and is prone to serious compromise of the security. The drawbacks of key oriented cryptographic techniques have resulted in the demand to develop keyless security schemes. This paper presents a novel keyless security scheme Reaction Automata Direct Graph (RADG), which is based on automata direct graph and reaction states. The novelty of RADG lies in the fact that it does not require any key to perform the cryptographic operations thus making it a feasible scheme for large wireless systems. Paper presents implementation of RADG and the results have shown that the hamming distance between individual cipher texts differ significantly a lot making the process of code breaking within the large systems very difficult compared to the schemes that rely on classical cryptography. The Security analysis of RADG proves that it is cryptographically sound in terms of confidentiality, integrity and non-repudiation

Energy efficiency and superlative TTT for equitable RLF and Ping Pong in LTE networks

Data hungry users engage radio resources over long periods of time thus resulting into higher energy consumption by Base Stations (BSs). Mobile operators’ operational expenditure (OPEX) is directly affected by augmented electricity bills due to increased power consumption, thereby ensuing reduced economic and environmental benefits, i.e. profitability of vendors and green communication accordingly. This work provides performance analysis of our proposed reduced early handover (REHO) scheme which results in increased energy efficiency. Impact of reduced energy consumption is shown on OPEX, as well as greener aspects are investigated by inclusion of real life commercial tariffs adopted by one of the mobile operators in the UK. Performance analysis revealed that varying time to trigger (TTT) values significantly impact radio link failure (RLF), ping pong effect as well as call drop ratio (CDR) and Handover ratio (HOR), at changing users’ velocities. Paper investigates and provides a very useful insight for superlative value of TTT for unbiased RLF and Ping Pong, which can help vendors not only to achieve increased energy efficiency, but also maintain other salient performance parameters within acceptable limits. The work also achieves the fact that the time difference in terms of transmission time intervals (TTIs) for reduced early handover in REHO, always remain the same irrespective of the value of TTT, thus ensuring that REHO continuously achieves increased energy efficiency compared to LTE standard