Teemu Savolainen

Networking solutions for connecting bluetooth low energy enabled machines to the internet of things

The next wave driving the expansion of the Internet will come from the Internet of Things. Bluetooth LE is a rapidly emerging ultra-low-power radio technology expected to be incorporated in billions of IoT devices in the next few years. Consequently, it is particularly important to specify Internet connectivity solutions for Bluetooth LE. In this article we present such solutions based on the ongoing standardization work in the IETF and Bluetooth Special Interest Group. We prove the feasibility of a complete IP-based protocol stack on constrained devices and illustrate its performance, highlighting key trade-offs. In addition, we discuss gateway operation covering global IPv6 connectivity and proxy-cache functionality.

Toward network controlled IP traffic offloading

Operator controlled IP traffic offloading in cellular networks has been a lively topic in both product and standard development during recent years. Specifically, 3GPP has developed multiple IP traffic offloading solutions for their system architecture, typically requiring 3GPP-specific modifications for user equipment. We argue that an adequate lightweight access technology agnostic IP traffic offloading system is achievable with a generic internet layer solution. Such a solution can still utilize 3GPP system properties for operators to push offloading policies securely into mobile devices. We discuss existing 3GPP-specified offloading solutions and present three variations of our internet layer traffic offloading implementations, and compare them against 3GPP-specified solutions. Our hands-on experience in operator networks shows that such a direction is feasible and promising.

IPv6 Addressing Strategies for IoT

In this paper, we analyze the suitability of different IPv6 addressing strategies for nodes, gateways, and various access network deployment scenarios in the Internet of Things. A vast number of things connected to the Internet need IPv6 addresses, as the IPv4 address space was effectively consumed before the introduction of the Internet of Things. We highlight how the heterogeneity of nodes and network technologies, extreme constraint and miniaturization, renumbering, and multihoming, present serious challenges toward IPv6 address allocation. By considering the topologies of various types of IoT networks, their intended uses as well as the types of IPv6 addresses that need to be deployed, we draw attention to allocation solutions as well as potential pitfalls.

Bridging the gap between internet standardization and networking research

The participation of the network research community in the Internet Standards Development Organizations (SDOs) has been relatively low over the recent years, and this has drawn attention from both academics and industry due to its possible negative impact. The reasons for this gap are complex and extend beyond the purely technical. In this editorial we share our views on this challenge, based on the experience we have obtained from joint projects with universities and companies. We highlight the lessons learned, covering both successful and under-performing cases, and suggest viable approaches to bridge the gap between networking research and Internet standardization, aiming to promote and maximize the outcome of such collaborative endeavours.

NAO: a framework to enable efficient mobile offloading

Offloading mobile data traffic away from cellular networks has become a main concern for mobile operators to guarantee the quality of service of various applications offered to end-users. Given the explosive growth of smartphone users and mobile data traffic, it is crucial to develop efficient and scalable mechanisms to meet the increasing demand of network capacity. To address the challenge, we propose the Network-Assisted Offloading (NAO), a framework that utilizes network assistance to promote offloading performance and energy saving on mobile hosts. We advocate that an efficient, simple to deploy, and with absolutely minimal or no changes to an end host solution is the key to achieving effective offloading in current and future mobile networks. Compared to solely host-based solutions, our approach explores a new angle to address the offloading challenge through network assistance.

Speeding up IPv6 transition: Discovering NAT64 and learning prefix for IPv6 address synthesis

During the transition from IPv4 to IPv6 hosts in IPv6-only networks need to communicate with IPv4 hosts as most of the Internet services are not yet supporting IPv6. Hosts with IPv6 access would benefit from discovering the presence of NAT64 and learning a prefix needed for IPv6 address synthesis. We propose two mechanisms and systematically evaluate the existing solutions in this area. Based on our comparison of the existing solutions and practical implementation experience, we recommend the heuristic discovery method which is now adopted in the IETF1 transition toolbox for the IPv6 Internet.

Evolving the 3GPP bearer model towards multiple IPv6 prefixes and next-hop routers

The 3GPP architecture is not particularly IPv6 friendly when it comes to handling of multiple prefixes. The excess use of default bearers and related radio access bearers to mimic multi-addressing is not efficient, resource-wise. This paper proposes to enhance the existing Evolved Packet System bearer model to allow a bearer to have multiple IPv6 prefixes as well as multiple next-hop routers for the sake of a better network controlled traffic steering. The solution has a minimal delta to the existing 3GPP system architecture and offers excellent migration path to the new functionality. While the proposed solution advocates local traffic breakouts and use of localized network resources along with multi-addressing, it does not even attempt to change the Packet Data Network Gateway centric mobility management nature of the 3GPP architecture. The enhancements on the bearer model are based on the design principle that IPv6 prefixes meant for localized network access do not need mobility, thus reducing the amount of system level signaling during mobility events. The solution works only for IPv6, while the existing IPv4 functionality is kept intact. This paper describes in detail the new bearer model, including an extensive discussion of how IPv6 is supposed to be implemented on top of it, and analyzes the impact of required changes and the backward compatibility with the existing Evolved Packet System.

Measuring energy consumption for RESTful interactions in 3GPP IoT nodes

As the Internet of Things (IoT) evolves to encompass ever increasing quantities of smart devices, sensors and other smart objects, attention must be paid to considering what kinds of wireless networks should be employed, and the data transfer protocols to be used to allow communication among these entities. It is highly important that energy consumption for communication remains as minimal as possible. In this paper we present power consumption measurements in end devices, when REST-based resource retrieval is performed with HTTP and CoAP over 3GPP EDGE, HSPA and LTE networks. Our findings are based on actual measurements taken over the radio interface of a mobile handset in live cellular networks, and show that for a few transactions of small packet sizes, HTTP performs comparatively well in terms of power consumption. Also, power consumption is lowest in the handset when EDGE is used, but an LTE network with operator assisted power savings approaches power consumption levels seen with EDGE. Finally, for sessions consisting of large number of transactions, we show that using CoAP over the WebSocket protocol results in significantly less power consumption compared to HTTP.