Search

Providing "connectivity from the sky" is the new innovative trend in wireless communications. High and low altitude platforms, drones, aircrafts and airships are being considered as the candidates for deploying wireless communications complementing the terrestrial communication infrastructure. In this article, we report the detailed account of the design and implementation challenges of an aerial network consisting of LTE Advanced (LTE-A) base stations. In particular, we review achievements and innovations harnessed by an aerial network composed of Helikite platforms. Helikites can be raised in the sky to bring Internet access during special events and in the aftermath of an emergency. The trial phase of the system mounting LTE-A technology onboard Helikites to serve users on the ground showed not only to be very encouraging but that such a system could offer even a longer lasting solution provided that inefficiency in powering the radio frequency equipment in the Helikite can be overcome., Comment: IEEE Communications Magazine 2016

The meaning of 5G is still a subject of discussion in the industry. However, the softwarization of networks is expected to shape the design, operation and management of 5G networks. The opportunity is then crucial for Telcos, vendors and IT players to consider the management of 5G networks during its design time and avoid the build it first, manage it later paradigm. However, network softwarization comes with its own set of challenges, including robustness, scalability and resilience. In this paper, we focus on the importance of resiliency and propose a Self-Healing based framework for 5G networks to ensure services and resources availability.

The 4G Long Term Evolution (LTE) is the cellular technology expected to outperform the previous generations and to some extent revolutionize the experience of the users by taking advantage of the most advanced radio access techniques (i.e. OFDMA, SC-FDMA, MIMO). However, the strong dependencies between user equipments (UEs), base stations (eNBs) and the Evolved Packet Core (EPC) limit the flexibility, manageability and resiliency in such networks. In case the communication links between UEs-eNB or eNB-EPC are disrupted, UEs are in fact unable to communicate. In this article, we reshape the 4G mobile network to move towards more virtual and distributed architectures for improving disaster resilience, drastically reducing the dependency between UEs, eNBs and EPC. The contribution of this work is twofold. We firstly present the Flexible Management Entity (FME), a distributed entity which leverages on virtualized EPC functionalities in 4G cellular systems. Second, we introduce a simple and novel device-todevice (D2D) communication scheme allowing the UEs in physical proximity to communicate directly without resorting to the coordination with an eNB., Comment: Submitted to IEEE Communications Magazine

Hybrid aerial-terrestrial communication networks based on Low Altitude Platforms (LAPs) are expected to optimally meet the urgent communication needs of emergency relief and recovery operations for tackling large scale natural disasters. The energy-efficient operation of such networks is important given the fact that the entire network infrastructure, including the battery operated ground terminals, exhibits requirements to operate under power-constrained situations. In this paper, we discuss the design and evaluation of an adaptive cooperative scheme intended to extend the survivability of the battery operated aerial-terrestrial communication links. We propose and evaluate a real-time adaptive cooperative transmission strategy for dynamic selection between direct and cooperative links based on the channel conditions for improved energy efficiency. We show that the cooperation between mobile terrestrial terminals on the ground could improve the energy efficiency in the uplink depending on the temporal behavior of the terrestrial and the aerial uplink channels. The corresponding delay in having cooperative (relay-based) communications with relay selection is also addressed. The simulation analysis corroborates that the adaptive transmission technique improves the overall energy efficiency of the network whilst maintaining low latency enabling real time applications., Comment: To Appear In IEEE Transactions On Aerospace And Electronic Systems, 2014

This paper introduces a rapidly deployable wireless network based on Low Altitude Platforms and portable land units to support disaster-relief activities, and to extend capacity during temporary mass events. The system integrates an amalgam of radio technologies such as LTE, WLAN and TETRA to provide heterogeneous communications in the deployment location. Cognitive radio is used for autonomous network configuration. Sensor networks monitor the environment in real-time during relief activities and provide distributed spectrum sensing capacities. Finally, remote communications are supported via S-band satellite links., Comment: Accepted at 5th EAI PSATS Conference, June 27-28, 2013

Energy efficiency in wireless networks has become an important field of research due to ever increasing energy expenditure in battery supplied mobile terminals. In this paper we present an energy efficient routing scheme for multi-standard infrastructure wireless networks based on multi-hop cooperative relaying. The aim of the proposed technique is to exploit short-range cooperation to take benefit from mobile terminals having superior links thus enable energy efficiency. Performance results show that higher data-rate yielded by cooperation can compensate the expense of higher energy due to multiple interfaces active on the same mobile terminal, making possible to observe energy efficiency gain of the system. A maximum achievable energy efficiency gain of up to 42 % was observed in our simulations when using the cooperative short range routing technique., Comment: Accepted at IEEE VTC-Spring Conference 2013, Dresden, June 2013

The traditional model of single ownership of all the physical network elements and network layers by mobile network operators is beginning to be challenged. This has been attributed to the rapid and complex technology migration compounded with rigorous regulatory requirements and ever increasing capital expenditures. These trends, combined together with the increasing competition, rapid commoditization of telecommunication equipments and rising separation of network and service provisioning are pushing the operators to adopt multiple strategies, with network infrastructure sharing in the core and radio access networks emerging as a more radical mechanism to substantially and sustainably improve network costs. Through infrastructure sharing, developing countries and other emerging economies can harness the technological, market and regulatory developments that have fostered affordable access to mobile and broadband services. Similarly, the network operators entering or consolidating in the emerging markets can aim for substantial savings on capital and operating expenses. The present paper aims to investigate the current technological solutions and regulatory and the technical-economical dimensions in connection with the sharing of mobile telecommunication networks in emerging countries. We analyze the estimated savings on capital and operating expenses, while assessing the technical constraints, applicability and benefits of the network sharing solutions in an emerging market context.

Heterogeneous wireless networks with wireless devices supporting multitude of radio access technologies are witnessing increasing interest from network providers and consumers alike. Energy efficiency in such networks has become an important design consideration due to the limited battery life of mobile terminals on one side, and the ever increasing operational expenses pertaining to energy expenditure on the other. In this paper, we present a routing protocol for multi-radio multi-hop wireless networks, which aims to achieve a trade-off between energy consumption in the network and routing delay, considering both the energy consumption at the devices and the link energy costs. We also present optimum route-path selection strategies by defining a utility function to minimize the energy consumption in the network while maximizing the network lifetime. Using simulations, we verify the utility of the route-path selection strategies and the efficiency of the energy aware routing algorithm. It turns out that the proposed protocol is energy efficient in terms of path selection, with a slight compromise in the end-to-end delay., Comment: to be re-submited later after extending the article

Aerial telecommunications networks based on Low Altitude Platforms (LAPs) are expected to optimally meet the urgent needs of emergency relief and recovery operations for tackling large scale natural disasters. The energy efficient operation of such networks is important given the fact that the entire network infrastructure including the battery operated ground terminals, exhibit requirements to operate under power constrained situations. In this paper, we propose and evaluate a real-time adaptive transmission strategy for dynamic selection of direct and cooperative links based on the channel conditions for improved energy efficiency. We show that the cooperation between mobile terrestrial terminals on the ground could improve the energy efficiency in the uplink depending on the temporal behavior of the terrestrial and the aerial uplink channels. The simulation analysis corroborates that the adaptive transmission technique improves the overall energy efficiency of the network., Comment: This paper has been withdrawn

This paper outlines how an aerial telecommunications network can optimally meet the stringent needs of emergency relief and recovery operations. We propose a novel architecture, made of an integrated and highly dynamic multi-purpose aerial telecommunications infrastructure that can be contextually extended with fast-deploying high or low altitude platforms. In particular, we analyze the interest and challenges of adapting core concepts from substitution networks and controlled mobility mechanisms, so that a base network can be seamlessly augmented, both in terms of capacity and functions. We give an estimation of the emergency traffic supported by the lower altitude platforms in an example scenario and discuss the challenges posed by this architecture, notably in terms of disaster resilience and ability to efficiently provide sustained first responder communications.