Fourth Generation Mobile Systems Research Articles

A coupled‐fed loop antenna for fourth generation mobile system applications

AbstractThis article proposes a compact printed meander loop antenna for the fourth generation (4G) mobile system applications.The total length of the meander loop operates a one‐wavelength resonant mode (mode 1) at 774 MHz. To increase the antenna's operation bandwidth, this article uses coupled‐fed feeding method that contains a coupling patch connected with a 50‐Ω microstrip feed line. By applying the coupled‐fed method, a new one‐wavelength resonant mode (mode 2) is excited. After carefully adjusted the size of coupling patch, the frequency of mode 2 shifts to 904 MHz combining with mode 1 to form dual broad operations bands. The measured dual broad bands from 658 to 963 MHz and from 1658 to 2693 MHz can be applied in the 4G mobile system, especially for the long‐term evolution application. The two resonant modes are resonated by 1λ loop type that has less influence by changing the size of ground plane. The antenna portion and overall dimensions of the proposed antenna are 20 × 60 × 0.8 mm3 and 120 × 60 × 0.8 mm3 suitable for today's mobile phone application. With the advantages of board band, compact size, low cost, and good performance, the proposed antenna appears to be a promising candidate for the 4G mobile applications. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1900–1907, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26927

A Velocity-Based Bicasting Handover Scheme for 4G Mobile Systems

We propose a velocity-based bicasting handover scheme for the efficient utilization of backhaul network resources in fourth-generation mobile systems. The original bicasting handover scheme adopts the mechanism of holding the data of a mobile station (MS) in all potential target base stations in advance, before the actual handover execution of the MS. The scheme minimizes the packet transmission delay caused by handover and achieves the goal of seamless connectivity, however, it results in an aggressive consumption of the backhaul network resources. Moreover, as the scheme gets widely adopted for high data rate real-time services and the demand for these services grows, the amount of the resources consumed due to the bicasting will increase tremendously. In this paper, we present a new bicasting handover scheme that reduces the data bicasting time, thereby improving the backhaul network resource utilization. Our scheme exploits the velocity parameter of MS and introduces a novel concept of bicasting threshold determined for the specific mobile speed groups. Simulations prove the efficiency of our scheme over the original one in overcoming the aggressive resource consumption at the backhaul network.

Scenarios and business models for 4G in Europe

This paper investigates the main trends and uncertainties that will define fourth generation mobile systems and services (4G) in Europe. It outlines two divergent visions on 4G: the so‐called “immediate” 4G vision, consisting of wireless local area networks (WLANs) combined with other wireless access technologies, competing with 3G in the short term, and the so‐called “linear” 4G vision, in which the 3G standard is not replaced until the end of its life cycle by an ultra‐high speed broadband wireless network. Which of these visions will materialise, and what this means for the competitiveness of the main 4G stakeholders in Europe, will be to a large extent determined by which business models are feasible for 4G.

Challenges in the migration to 4G mobile systems

With the rapid development of wireless communication networks, it is expected that fourth-generation mobile systems will be launched within decades. 4G mobile systems focus on seamlessly integrating the existing wireless technologies including GSM, wireless LAN, and Bluetooth. This contrasts with 3G, which merely focuses on developing new standards and hardware. 4G systems supports comprehensive and personalized services, providing stable system performance and quality service. However, migrating current systems to 4G presents enormous challenges. In this article, these challenges are discussed under the headings of mobile station system, and service aspects. Proposed solutions to the research problems in each aspect are also examined.

Universal broadband mobility target for post-TINA infrastructure: toward the fourth generation

Future universal broadband mobile services present a challenge for telecommunications architectures, control, and management. The focus of the future mobile (fourth) generation vision is turned from capacity to services, from radio to network-wide issues. New types of applications will evolve that should be supported by an adequate programmable intelligent telecommunications infrastructure. A convergence between telecom and datacom networks will happen based on the communications middleware concept, which will provide universal secure connectivity between mobile users and their applications. Actual specifications of TINA-C do not address all such necessary issues. There is a need for technology evolution, enhancement, and integration to meet these new requirements at different levels. The author the concept of the universal broadband mobile telecommunications systems (UBMTS, or simply UBM) described as fourth-generation mobile systems. The UBMTS objective is both to extend mobile user access to the range of broadband services that will exist for broadband integrated services digital network (B-ISDN) users, and to extend the customization of new services related to personal communications systems (PCS) users.