Markku Jokinen

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.

LE-WARP: Linux enriched design for wireless open-access research platform

Linux Enriched (LE) - WARP is a programmable radio platform that can be configured to build experimental and recon-figurable wireless networks. Through LE-WARP design, we introduce a system level modification to WARP. Achieved end result is a software enhanced WARP SW/HW design called LE-WARP. It enables adaptation across various layers of communication protocol like network, transport and application layers along with the already supported flexibility at physical and MAC layers on WARP. This paper provides the technical details of the modifications made in terms of software, system architecture and performance comparison between the default OFDM reference design and the LE-WARP design on WARP.

Demonstration of distributed TDMA MAC protocol implementation with OLSR on linux enriched WARP

In this demo we present software extension for the Wireless open Access Research Platform (WARP), named as Linux Enriched WARP (LE-WARP). The objective of the LE-WARP is twofold. First, to make the WARP more independent from external systems, e.g., need for external PC to be part of the WARPs network layer. This is achieved by introducing Linux OS to the platform. The second objective is to utilize a secondary network for coordinated statistics gathering from the WARPs. To demonstrate these features of LE-WARP, a prototype implementation consisting of distributed Time Division Multiple Access (TDMA) based MAC protocol with distributed time synchronization algorithm and the Optimized Link State Routing (OLSR) protocol for ad hoc networks is presented. The demonstration highlights the LE-WARPs ability to monitor the multihop test network consisting four nodes while utilizing the presented prototype implementation.

Implementation of OpenFlow based cognitive radio network architecture: SDN&R

The static conventional network architecture is ill-suited to the growing management complexity and highly dynamic wireless network topologies. Software Defined Radio systems and their extension to cognitive and smart radio are characterized by distinct control loops for management which constantly increase network complexity and management inefficiencies, due to clear-cut between radio and core network management. Adding numerous devices and networks together will constantly increase the management cost, thus hinders scalability. Therefore, a holistic solution to synchronize radio and networks status has an elevated demand. To interconnect these systems and devices together, there is a need for a common management interface. OpenFlow is the first standard interface that enables Software Defined Networking (SDN). It can be rolled out in a variety of networking devices to enable improved automation and management by using common Application Program Interfaces to abstract the underlying networking details. The Software Defined Networking & Radio (SDN&R) framework proposed here has a potential combination between SDN and Radio networks to discover the underlying dynamism in cognitive access networks with integrated radio management. By isolating the control plane from the data plane, SDN&R enables a flexible management framework empowered by end-to-end goals through OpenFlow. In this article, we propose, validate, and evaluate the SDN&R architecture. In doing so, first we implement the OpenFlow enabled cognitive basestations (BSs) on Wireless Open-Access Research Platform. Furthermore, we develop software agents on BSs to provide radio status information to the cognitive control application implemented on the SDN controller. The results verify that the proposed framework in-lines with layer-2 or layer-3 forwarding performance. We claim that this work represents the first successful implementation results which synergizes SDN with Cognitive networks that motivates researchers towards SDN based radio resource management.

SDN Core for Mobility between Cognitive Radio and 802.11 Networks

In this paper, we implement an Open Flow based fully functional 802.1X access network and an IP based cognitive access network which are interconnected as edge networks to our SDN core. We realize seamless mobility in the WLAN domain and mobility between WLAN and Cognitive networks for the clients with dual band support. The pre-installed flows on the backbone aggregate traffic from access networks and forward in-between. We implement an access control mechanism integrated with DHCP, to prevent unregistered users accessing the network. This work seems to be the first realization of integration of an IP based cognitive network and Open Flow enabled fully functional WLAN into SDN core. Our results elaborate throughput measurements and an extensive description of TCP characteristics based on tcpdump traces in-between WLAN and cognitive clients. The results reveal, that the delay is within the limits of most delay sensitive applications, such as VoIP and gaming.

A channel allocation algorithm for Citizens Broadband Radio Service/Spectrum Access System

Recently, the Federal Communications Commission has proposed to create Citizens Broadband Radio Service (CBRS) with the three-tier spectrum sharing system to release more spectrum for the mobile broadband usage in the United States. At the moment, the Wireless Innovation Forum is involved in defining the operational and functional requirements for this framework based on [1], and also in standardizations. Evidently, the successful operation of this system depends on efficient channel allocation algorithms. In this paper, we consider the CBRS with the three-tier spectrum sharing system. A set of CBRS users, i.e., Priority Access License (PAL) and General Authorized Access (GAA) users are located in an area, which is divided into multiple census tracts. The PAL and GAA users request frequency channels from the spectrum access system (SAS). The role of the SAS is to allocate channels to these two types of users while providing interference protection to the incumbent users. For this setup, we consider the problem of channel allocation for PAL and GAA users. The objective is to allocate channels for these two types of users, while considering the channel allocation rules proposed in [1]. For this problem, we propose a channel allocation algorithm to be used by the SAS. The proposed algorithm allocates channels to the CBRS users in two steps: 1) allocate channels to the PAL users and 2) allocate channel to the GAA users. Numerically, we show that the proposed algorithm is able to allocate channels while satisfying the rules proposed in [1]. More importantly, this research provides new insights on investigating channel allocation algorithms in CBRS/SAS.

Minimum Separation Distance Calculations for Incumbent Protection in LSA

In this paper, we consider minimum separation distance calculations from the perspective of a real-life Licensed Shared Access (LSA) system in the 2.3 GHz band in Europe. In the LSA system, an LTE network shares spectrum resources with incumbent users, such as programme making and special events (PMSE) users, which need to be protected from harmful interference. Plenty of potential resources are available, in case the incumbent activity is occasional or localized. The sharing scenario requires realistic separation distances to be calculated to protect the incumbents. The minimum separation distances were calculated using methods presented in the ECC report on compatibility studies on 2.3 GHz band, but by using the parameters from the real-life LSA test network. With this work, we bridge the gap between theoretical research for incumbent protection and practical LSA deployment. In the process of defining new separation distances, discrepancies were found in the original example calculations.

Linux Enriched Design in Third Generation Wireless Open Access Research Platform

This paper describes embedded Linux system implementation on third generation Wireless Open Access Research Platform (WARP v3). The purpose of this implementation is to integrate operating system (OS) with radio communication system to accomplish flexible and stand-alone communication node for testing different wireless communication protocols. Achieved Linux Enriched WARP v3 (LE-WARP v3) design is a dual (micro-processing) core implementation on field-programmable gate array (FPGA) with Linux running on one core, medium access control (MAC) implemented on other core directly interfacing radio peripherals. Inter-processor communication between both cores is implemented. Hence, achieved result is a versatile system which allows altering any layer of communication network stack, making it practical to test algorithms and prove concept solutions in real-time environment.