The widespread of a Wireless Local Area Network (WLAN) access network in residential areas provides low-cost and high-speed access to the Third-Generation Partnership Project (3GPP) services for end ...users. This has virtually made WLAN to be a complementary access network to Universal Mobile Telecommunications System (UMTS). The interoperability of WLAN and UMTS is made possible with the use of a mobility management mechanism in IP Multimedia Subsystems (IMS) architecture. Current problems in mobility management mechanisms are found in device mobility such as mobile phones. Such problems affect several layers and disrupt services. In this paper, IMS mobility management mechanisms with G1 mobile phone as an IMS client testbed is implemented, and its impact on the Quality of Experience (QoE) during end-to-end VoIP call session and its conformity to the 3GPP requirements of seamless service continuity is evaluated. The QoE driven mobility management mechanism is then proposed and evaluated to improve the QoE and to meet the 3GPP requirements of seamless service continuity during the handover between UMTS and WLAN access networks. Preliminary results show that there is an improvement in QoE and the requirements of 3GPP service continuity were met. The proposed Quality of Service (QoS) driven mobility management mechanism will help in the development of dual-mode mobile handsets with QoE adaptability.
The article presents the application of a new analytical model of the full-availability group carrying a mixture of different multi-rate traffic classes with compression property for modeling the ...WCDMA radio interface with packet scheduling. The proposed model can be directly used for modeling of theWCDMA interface in the UMTS network servicing different traffic classes. The described model can be applied for a validation of the efficiency of the WCDMA interface measured by the blocking probability and the average carried traffic for particular traffic classes.
Universal Mobile Telecommunications System (UMTS), is the third generation (3G) of mobile communication which is based on the wideband code division multiple access (W-CDMA) radio access to provide ...bandwidth and spectral efficiency. Interference in 3G system is significantly lower compared to the preceded generations. However, it does not mean 3G is free from the issues associated with interferences, such as low signal quality and call drop. The interference level in UMTS can be measured by using the well-known parameter Received Total Wideband Power (RTWP). This parameter is affected by many factors such as number of the users connected to the system, combining second generation (2G) and 3G frequencies within the same geographical area, geographical causes (difference of Altitude), and hardware impairment. In this paper we intensively study how these factors affect the uplink interference level (i.e. RTWP value) in 3G system used by a particular telecommunications company, Asiacell company, Iraq. The obtained data shows that call drop is the most serious issue raised due to high value of RTWP in 3G system. We demonstrate that system enhancement, in terms of lower RTWP level, are obtained by adding second carrier to the sites, separating 2G band from 3G band using special filter, and optimizing the hardware components.
5G smart antenna for IoT application: A review Kishore, Nawal; Senapati, Anupama
International journal of communication systems,
10 September 2022, Letnik:
35, Številka:
13
Journal Article
Recenzirano
Summary
The fifth generation of mobile technology is referred to as “5G.” 5G refers to the next significant phase of mobile communications standards after the upcoming 4G standards. With 5G ...technology, the bulk of high‐bandwidth consumers would be able to use their phones in innovative ways. When 5G is pushed over a VOIP‐enabled device, individuals encounter record levels of call volume and data transmission. In this paper, we reviewed smart antenna 5G for Internet of Things (IoT) application. Beamforming is a 5G active antenna technique that uses directional radio links to concurrently and selectively supply high bandwidth to certain mobile devices. Multi‐antenna systems are required when using larger frequency ranges. The better the propagation conditions for electromagnetic waves, the higher the frequency. To some extent, multi‐antenna arrays and beamforming can assist mitigate this. Radio signals can be transmitted and received in a spatially targeted manner due to beamforming. The better the beamforming works, the more dipoles (antenna elements) are available. In contrast to earlier eras on wireless networking, such as Global System For Mobile Communication (GSM), Universal Mobile Telecommunication System (UMTS), also 4G/LTE, 5G would not require major technological advances. Additional systems and equipment are added to the existing LTE technology to increase data capacity and reduce latency. The 5G NR infrastructure depends heavily on active antenna arrays, which enable multi‐user multiple‐in multiple‐out (MIMO) technologies. For targeted radio contact with the receiver, these antenna modules use beamforming.
The Signalling System No. 7 (SS7) is used in GSM/UMTS telecommunication technologies for signalling and management of communication. It was designed on the concept of private boundary walled ...technology having mutual trust between few national/multinational operators with no inherent security controls in 1970s. Deregulation, expansion, and merger of telecommunication technology with data networks have vanquished the concept of boundary walls hence increasing the number of service providers, entry points, and interfaces to the SS7 network, which made it vulnerable to serious attacks. The SS7 exploits can be used by attackers to intercept messages, track a subscriber's location, tape/redirect calls, adversely affect disaster relief operations, drain funds of individuals from banks in combination with other methods and send billions of spam messages. This paper provides a comprehensive review of the SS7 attacks with detailed methods to execute attacks, methods to enter the SS7 core network, and recommends safeguards against the SS7 attacks. It also provides a machine learning based framework to detect anomalies in the SS7 network which is compared with rule based filtering. It further presents a conceptual model for the defense of network.
A stable and nationwide mobile network coverage is increasingly regarded as essential. This requires an expansion of mobile networks throughout the country. However, the installation of masts and ...antennas has often been the subject of conflict in Germany, especially due to fears about potential health effects of electromagnetic fields. Transmitters become both a trigger and a target of social protests. From a discourse-theoretical perspective, we identify central lines of argumentation in the German cellular network conflicts. A triangulation of quantitatively oriented and qualitative analysis components forms the methodological basis. Regional case studies provide an opportunity to identify local differences. A comparison of past and recent conflicts reveals discursive shifts over time. Debates about the possible health effects of mobile radio were particularly contentious in the context of UMTS mobile phone expansion at the turn of the millennium. The (planned) installation of transmitters at the local level often sparked this discussion. During the expansion of the 5G network, in addition to the debate about the health risks of the technology, questions are now being raised about whether and to whom the expansion is necessary. Compared to the previous period of investigation, local conflicts about transmitters now appear to be less virulent and can be found primarily in southern and southwestern Germany.
Overcoming the challenge of battery recharging and replacement in industry Internet-of-Things (IoT) applications is considered by proposing the design of a triple-band high-gain multibeam ambient ...radio frequency (RF) energy harvesting system utilizing hybrid combining. The novelty of the design is that it simultaneously exploits frequency, space, and polarization to maximize the harvested RF energy. Wideband hybrid combining is proposed, which enables the harvesting of energy at low RF power densities while maintaining the wide frequency and space coverage necessary for ambient RF energy harvesting. The antenna design consisting of 16-ports has an average area per port of <inline-formula><tex-math notation="LaTeX">0.3\lambda \times 0.3\lambda</tex-math></inline-formula> (where <inline-formula><tex-math notation="LaTeX">\lambda</tex-math></inline-formula> is the freespace wavelength at 1.8 GHz) and is demonstrated to achieve a wide relative bandwidth of 38.5% covering the GSM-1800, UMTS-2100, and WiFi frequency bands. Hybrid combining of the 16-port antenna provides multiple antenna beams each with up to 11 dBi antenna gain and these provide broad beam coverage. The design for the rectifiers, using multistub impedance matching, is also provided and these are shown to be efficient over the frequency bands of interest. Measurements in an anechoic chamber demonstrate that the proposed energy harvesting system can provide an output dc voltage of more than 755 mV, an output dc power of more than <inline-formula><tex-math notation="LaTeX">-</tex-math></inline-formula>6.4 dBm and RF-to-dc efficiencies greater than 40% when the power density is more than 1400 <inline-formula><tex-math notation="LaTeX">\mu \mathrm{W}/\mathrm{m}^{2}</tex-math></inline-formula>. It is also shown that the proposed system can provide output dc power of 80 <inline-formula><tex-math notation="LaTeX">\mu \mathrm{W}</tex-math></inline-formula> and 7.3 <inline-formula><tex-math notation="LaTeX">\mu \mathrm{W}</tex-math></inline-formula> in real outdoor and indoor ambient environments, respectively.
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