Marko Palola

Cognitive Radio Trial Environment: First Live Authorized Shared Access-Based Spectrum-Sharing Demonstration

Cognitive radio system (CRS) technology can help respond to the growing mobile traffic demand by improving network resource usage and gaining access to new shared spectrum bands. This article presents a cognitive radio trial environment (CORE) consisting of cognitive engines (CEs) to control different radio systems [e.g., long-term evolution (LTE) and wireless open-access research platform (WARP)-based networks]. Load balancing and authorized shared access (ASA) are demonstrated using the trial environment with promising results. The ASA-based spectrum sharing trial is presented for the first time with a real-life mobile network accessing a shared spectrum band under a licensed shared access (LSA) regime. Cognitive decision making brings intelligence to the usage of the radio and network resources and, at best, increases considerably end users? quality of service (QoS) compared to the standard systems, as shown for QoS-based offloading.

Spectrum sharing using licensed shared access: the concept and its workflow for LTE-advanced networks

Spectrum sharing between an existing incumbent spectrum user and an LTE/LTEAdvanced network with conditions that resemble exclusive licensing have become an appealing solution for mobile network operators to respond to the growing traffic and spectrum demand in a timely manner. While traditional exclusive licensing continues to be the preferred option for MNOs, the new sharing- based licensed shared access (LSA) concept is receiving growing interest in research, regulation and standardization. When applied to mobile communications, the LSA concept would allow an MNO to share spectrum from another type of incumbent spectrum user under a regulator¿s supervision with predetermined rules and conditions that guarantee operational certainty for both MNO and incumbent. This article reviews different types of spectrum bands for LTE/LTE-Advanced and beyond networks, and focuses on the LSA concept as a spectrally efficient solution for spectrum access in the future. The article identifies the key stakeholders, including the incumbent spectrum user, the MNO, and the regulator, and their roles in the LSA concept. The key elements in the LSA concept are reviewed, and a work flow for the life cycle of the LSA concept is proposed, consisting of LSA preparation, licensing, deployment, and release phases. The tasks of the key stakeholders in the different phases of the LSA work flow are discussed. The LSA concept can offer a complementary approach to traditional exclusive licensing and license-exempt operations with features that benefit all involved stakeholders. It can be realized with reasonable modifications to the existing network infrastructure and regulatory framework with two new elements for managing the varying spectrum availability: the LSA Repository and LSA Controller.

An evolution toward cognitive cellular systems: licensed shared access for network optimization

This article reviews the application of the recent European Licensed Shared Access (LSA) concept for spectrum sharing between a mobile network operator (MNO) and an incumbent user. LSA, as a new area of application of cognitive technology, provides the MNO an opportunity to access new frequency resources on a shared basis. The article presents critical design criteria of LSA from the MNO point of view in order to allow future cognitive cellular networks to efficiently exploit shared spectrum bands. We describe the role of LSA bands in the context of heterogeneous networking, and identify the Long Term Evolution (LTE) and LTE-Advanced enabling technologies that support the introduction of LSA. Such technologies include traffic steering, carrier aggregation, and self-organizing networking. Additionally, we introduce an LSA management unit controlled by the MNO, to be implemented on top of the existing LTE/LTEAdvanced architecture, and we discuss the functionalities required for the optimization and automation of LSA resource management. We also depict the interrelations of the tasks between the LSA management unit and the supporting LTE/LTE-Advanced technologies. Based on the findings in this article, the ongoing cellular system evolution is shown to form a solid base for the introduction of new shared spectrum bands for cognitive cellular systems.

A mobile phone-based context-aware video management application

We present a video management system comprising a video server and a mobile camera-phone application called MobiCon, which allows users to capture videos, annotate them with metadata, specify digital rights management (DRM) settings, upload the videos over the cellular network, and share them with others. Once stored in the video server, users can then search their personal video collection via a web interface, and watch the video clips using a wide range of terminals. We describe the MobiCon architecture, compare it with related work, provide an overview of the video server, and illustrate a typical user scenario from the point of capture to video sharing and video searching. Our work takes steps forward in advancing the mobile camera-phone from a video playback device to a video production tool. We summarize field trial results conducted in the area of Oulu, Finland, which demonstrate that users can master the application quickly, but are unwilling to perform extensive manual annotations. Based on the user trial results and our own experience, we present future development directions for MobiCon, in particular, and the video management architecture, in general.

MobiCon: integrated capture, annotation, and sharing of video clips with mobile phones

This paper presents MobiCon, a video production tool for mobile camera phones. MobiCon integrates video clip capture with context-aware, personalized clip annotation -- supporting automatic annotation suggestions based on context data and efficient manual annotation with user-specific ontologies and keywords -- and clip sharing secured by digital rights management techniques. Thus, MobiCon allows users to inexpensively create metadata-annotated video clips for a better management of their clip collections and keeps them in control of the clips they share.

Cognitive engine: design aspects for mobile clouds

A mobile cloud is a collaborative cluster of wireless devices exploiting their multiple air interfaces. It operates cognitively, i.e, collects information from the operating environment, from the results of its own operations etc., and then acts based on observations in order to fulfill the needs of the users. A cognitive engine is required for decision making and learning in a mobile cloud to efficiently exploit the available resources. This paper discusses the development and design of a cognitive engine for the mobile cloud scenario and investigates the practical implemention aspects. Moreover, simulation results show the advantages of learning in this kind of scenario.

Towards automating testing of communicational B3G applications

Mobile phones and laptop users are enjoying the fast and seamless Internet access provided by 3rd generation (3G) mobile technology, which allows the use of applications such as email, WWW, office tools, messaging, and communicating on the move. In the future beyond 3G (B3G) applications, networks and services will create many more opportunities for companies and individuals to use mobile phones in their everyday lives, in group work, information sharing, multi-user games and other purposes. In a mobile environment, these applications use online connections to complex network resources and other users and exchange data with them, for example to retrieve and publish content, collect and use context information from different sources, and use interactive value-added mobile network services such as billing, presence, streaming, and location-based services at the same time. Multiple online connections bring new challenges to the testing of B3G applications. In this paper, we discuss the new testing needs of B3G applications and present an experimental system for automating testing of B3G mobile applications that supports application testing in multiple mobile phones at the same time. We found that the available commercial testing tools support only one mobile phone at a time and therefore they do not efficiently support testing of B3G applications.

Field trial of Licensed Shared Access (LSA) with enhanced LTE resource optimization and incumbent protection

We present an end-to-end ecosystem trial of the Licensed Shared Access (LSA) concept using a live LTE network sharing the 2.3 GHz band with incumbent wireless cameras. The entire LSA concept is implemented introducing LTE network as an additional licensed user in the band with the aid of an LSA Repository for spectrum availability information from wireless cameras and an LSA Controller for managing the LTE network. The trial goes beyond previous LSA demos by presenting enhanced LSA resource optimization with LSA Controller that is integrated into a real network management system to coordinate a heterogeneous network of macro and small cells. Enhanced incumbent protection is provided with algorithms for tracking a moving incumbent and considering aggregate interference from the LTE network to incumbent. Trial gives a unique opportunity to see live how a commercial LTE network adapts transmissions on the fly according to the location of the incumbent. Small cells are shown to improve the LSA resource use as the enhanced incumbent protection algorithm can allow small cells to continue operations in situation where macro cells need to close down.

Field trial of the 3.5 GHz citizens broadband radio service governed by a spectrum access system (SAS)

In this paper, we describe a spectrum access system (SAS) based Citizens Broadband Radio Service (CBRS) field trial using a live LTE network in the 3.5 GHz band. The latest WInnForum specification guided the implementation of the relevant protocols for SAS operation. Here, we evaluate the performance of a CBRS field trial by using one of the most important performance indicators in a spectrum sharing scenario — the evacuation time. It indicates how rapidly the secondary user relinquishes the shared spectrum band to the primary user. Following the applied protocols, we measure and analyze the time scales for the evacuation and frequency change procedures in a field trial environment. Our work shows that the set time limits for the protection of primary users against interference are realistic when using commercially available mobile networks and equipment. Finally, utilizing knowledge of the latest base station models, we propose ways to reduce the evacuation and reconfiguration time by up to 70%.

Analysis of requirements from standardization for Licensed Shared Access (LSA) system implementation

Licensed Shared Access (LSA) is a novel flexible regulatory framework, which introduces a shared licensed use of a spectrum band to complement the existing exclusively licensed and license-exempt use. LSA as a general concept was first introduced by the European Commission already in 2011 and it has gained growing interest in standardization and regulatory forums in Europe since. To highlight its potential, European regulators have recently recognized LSA as a promising approach to provide mobile network operators (MNOs) access to the 2.3-2.4 GHz band. In this case, the protection of incumbent users introduces new requirements for information exchange between the incumbents and the mobile network. European Telecommunications Standards Institutes (ETSI) Reconfigurable Radio Systems (RRS) group has defined the requirements, which the LSA system needs to fulfil in order to enable mobile access to the 2.3-2.4 GHz band. This paper places LSA in the regulation and standardization landscape and presents a comprehensive overview of the activities in all relevant forums including their interrelations, to demonstrate the development of the concept. It specifically focuses on the standardization requirements on the LSA system, analyzes and maps the requirements from the ETSI RRS into the different functional blocks of the LSA architecture, and envisions how these can be taken into account in the system implementation. While the incumbent protection places a large number of new requirements on the mobile system design, the LSA system implementation is seen to be feasible by utilizing the existing LTE and LTE-Advanced features, and by developing the required new functionalities according to the standardization requirements.