Wireless personal area networking technologies for low-power Smart-Home applications

CONTENTS

1 Introduction
1.1 Background and Challenges
1.2 Scope and Outline of this Thesis

2 Wireless Networking Technologies
2.1 Wireless Body Area Network
2.2 Wireless Personal Area Network
2.3 Wireless Local Area Network
2.4 Wireless Campus Area Network
2.5 Wireless Metropolitan Area Network
2.6 Wireless Wide Area Network
2.7 Wireless Regional Area Network
2.8 Wireless Global Area Network

3 Smart Home
3.1 Wireless Home Entertainment Networks
3.2 Wireless Home Automation Networks
3.3 Wireless Machine-To-Machine Networks
3.4 Wireless Home Networks

4 Wireless Personal Area Networking Technologies
4.1 Bluetooth
4.1.1 Networking Architecture
4.1.2 Bluetooth Protocol Stack
4.1.3 Physical Layer
4.1.4 Medium Access Control Mechanism
4.1.5 Packet Frame Formats
4.2 Bluetooth Smart
4.2.1 Networking Architecture
4.2.2 Bluetooth Smart Protocol Stack
4.2.3 Physical Layer
4.2.4 Packet Frame Formats
4.3 UWB
4.3.1 Direct Sequence Ultra Wideband
4.3.2 Multiband Orthogonal Frequency-Division Multiplexing
4.3.3 Summary of UWB technologies
4.4 IEEE
4.5 ZigBee
4.5.1 Networking Architecture
4.5.2 ZigBee Protocol Stack
4.6 6LoWPAN
4.6.1 Networking Architecture
4.6.2 6LoWPAN Protocol Stack
4.7 Wi-Fi
4.7.1 Directional Communication
4.7.2 Physical Layer
4.7.3 Networking Architecture
4.7.4 Packet Frame Formats

5 Key Parameters

6 Evaluation and Comparison

7 Conclusion and Future Work

References
Bibliography
Webography

Listof Figures

Listof Tables

ABSTRACT

Wireless networking technologies are widely used in communication devices and services in almost every area of daily business. Medical environments, security authorities, and other organizations use them to increase their performance. In particular the Smart Home sector is one of the areas that has been researched extensively. From ecological and technological point of view, the opportunities for new technologies are vast. Therefore, it is important to compare such technologies using ecological parameters. This thesis will give an overview of the wireless network types, ranging from body area to global area networks, and introduces the different Smart Home networks. Furthermore, the major wireless networking technologies of personal area networks, Bluetooth, Bluetooth Smart, Ultra Wideband, ZigBee, Internet Protocol version 6 over Low-Power Wireless Personal Area Network and Wi-Fi, are discussed in detail. A comparison is made with current chipset manufacturers implementations to create a tabular overview of these technologies and their suitability in Smart Home networks. Results show that every technology has its optimal field of application in a modern Smart Home. However, it can be concluded that further experiments will show more accurate results.

Keywords: WPAN, Smart Home, Bluetooth, Bluetooth Smart, UWB, ZigBee, 6LoWPAN, Wi-Fi, 802.11ad

ZUSAMMENFASSUNG

Drahtlose Netzwerktechnologien zählen zum Rückgrad der Kommunikationseinrichtungen unseres tägli-chen Arbeitsalltags. In medizinischen Einrichtungen, Sicherheitsbehördern und anderen Organisationen werden diese Technologien zur Leistungssteigerung und zur Erhöhung der Effizienz eingesetzt. Zunehmend wird in letzter Zeit auch der Smart Home Sektor Ziel intensiver Forschung im Bereich der Netzwerktech-nologien. Aus ökologischer und technologischer Sicht ergeben sich Chancen für neue effizientere Techno-logien. Daher ist es wichtig, solche Technologien unter den Gesichtspunkten ökologischer Parameter zu vergleichen. Diese Arbeit gibt einen Überblick über die drahtlosen Netzwerktypen, die von körpernahen bis hin zu globalen Netzwerken reichen und erläutert die verschiedenen Smart Home Netzwerke. Aus dem Bereich der persönlichen Netzwerke werden die wichtigsten drahtlosen Netzwerktechnologien vorgestellt. Dabei werden Bluetooth, Bluetooth Smart, Ultra-Breitband, ZigBee, Internet Protocol Version 6 für Wireless Personal Area Network mit niedrigem Energieverbrauch und Wi-Fi ausführlich diskutiert. Ein Vergleich mit Implementierungen von Chip-Herstellern führt zu einer tabellarischen Übersicht dieser Technologien und schafft die Grundlage für die Beurteilung der Eignung in Smart Home Netzwerken. Die Ergebnisse zeigen, dass jede Technologie ihr optimales Einsatzgebiet in einem modernen Smart Home hat. Es kann jedoch der Schluss gezogen werden, dass künftige Experimente zur Eignung dieser Technologien im Smart Home diese Beurteilung vervollständigen können.

Keywords: WPAN, Smart Home, Bluetooth, Bluetooth Smart, UWB, ZigBee, 6LoWPAN, Wi-Fi, 802.11ad

1 INTRODUCTION

The operational area of wireless networking technologies is expanding vast. Due to new products, appli­cations and services, the rate of diffusion will keep growing over the next decade. According to the In­ternational Telecommunication Union (ITU) Information and Communications Technology (ICT) Facts and Figures, around 96.8 percent of the world’s population have an active mobile telephone subscription. Fig­ure 1.1 shows an overview of the global ICT developments from 2001 to 2015. The number of wireless devices has increased exponentially.¹

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Figure 1.1: Global ICT development, source: International Telecommunication Union (2015)

ICT is an important part of modern day business. Our relationships span world-wide using Social Media Services (SMS), such as Facebook or LinkedIn. Additionally, the machines we are using every day are already creating their own ICT network, the Internet of Things (IoT). The IoT is offering a vast amount of opportunities for new products and services, especially to the Smart Home market.

The modern art of living is an emerging market for smartness in our homes. Today, around 5 million house­holds in Europe have installed Smart Home systems. This number will increase over 30 million by the end of this decade.²

Research and Technical Development (RTD) engineers are challenged to create the products and services to fulfill the requirements of a Smart Home. A wide range of networking standards, protocols and tech­nologies were developed to meet certain requirements. Especially technical product managers and RTD engineers of the ICT industry are the target audience of this thesis.

This thesis will introduce the requirements of modern Smart Homes and outline the key wireless networking technologies available for personal networks in Smart Homes. The information is based on data from various sources, such as articles, research papers and books. Finally, this thesis present a guidance for selecting these networking technologies for energy efficient Smart Home applications.

1.1 Background and Challenges

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Figure 1.2: Wireless network scenario in a Smart Home environment, source: Own diagram

To explain the significance of a guidance in energy efficient wireless networking in Smart Homes, this thesis uses a simple scenario of a wireless network as shown in figure 1.2. The device nodes A, B, C, D and E communicate with each other over the wireless links L1 to L5. Even in this simple scenario it is difficult for an RTD engineer to choose the right wireless networking technology. Each wireless link addresses a specific task within a Smart Home environment. This thesis will try to capture the requirements for these tasks and match the wireless networking technologies to them.

Based on this simple scenario, the following research question can be posed: What are the key differences of wireless personal area networking technologies for selection in low-power Smart Home Applications?

1.2 Scope and Outline of this Thesis

The outline and flow of the thesis are shown in figure 1.3. Part I includes chapters 1 to 3. Chapter 1 presents the introduction, background and outline of this thesis. Chapter 2 introduces to the various wireless network types, from the body-near networks to satellite-based systems. In chapter 3, this thesis describes the organization, types and tasks of networks within a Smart Home. Part II starts in chapter 4 with an in-depth overview of essential wireless networking technologies used in Smart Homes. The key parameters for fur­ther evaluation are discussed in chapter 5. The thesis poses a guidance based on the gathered information in chapter 6. Finally, in chapter 7 the thesis will be concluded. Open research problems will be presented, that still need to be solved to have a comprehensive development guide for energy efficient Smart Home applications.

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Figure 1.3: Flow of the thesis, source: Own diagram

2 WIRELESS NETWORKING TECHNOLOGIES

Everyday we use networking technologies to exchange information. The ICT industry is the innovation and development engine of these technologies. They allow us to use information technology wherever and when­ever we need them. Whether it is in the office, at home, or on the way, ICT is available everywhere.³

There are many different technologies used to keep us connected to the global Internet by wire and wireless. More than 300 submarine cables are installed globally to interconnect all regions of the world using high­speed and high-capacity data routes. A vast number of access points builds the gap between the wired and the wireless ICT. The technologies used for wireless networks are commonly differentiated by their geographic range of operation.⁴

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Figure 2.1: Overview of the Wireless Network Types, adapted from: Latré et al. (2011): p. 6

Figure 2.1 shows an overview of the wireless network types, sorted in ascending order of their communi­cation range. They can be categorized into Wireless Body Area Network (WBAN), Wireless Personal Area Network (WPAN), Wireless Local Area Network (WLAN), Wireless Campus Area Network (WCAN), Wire­less Metropolitan Area Network (WMAN), Wireless Wide Area Network (WWAN), Wireless Regional Area Network (WRAN), and Wireless Global Area Network (WGAN).⁵

2.1 Wireless Body Area Network

Regarding their geographical coverage, the smallest is the WBAN. A WBAN covers an area of about one meter and has a very limited amount of throughput, which is the domain of health monitoring applications. Devices operating in a WBAN are for example wearables, attached to the body.⁶

The IEEE 802.15.6 standard define Physical and Medium Access Control layers for WBAN.⁷

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Figure 2.2: Typical WBAN scenario, source: Own diagram

Health and fitness applications use biosensors measuring biochemical interactions with the human body. Those signals are transmitted and monitored remotely. WBAN sensors, as shown in figure 2.2, allow users to operate freely without wires. This gives the individual maximum amount of mobility. A typical WBAN sensor system consists of a biosensor, a transmission unit, and a control and processing unit. They are used to monitor fitness or disease progression using typical parameters:⁸

- Temperature: Both the user and ambient temperature are measured by specific sensors and recorded for further processing and evaluation.
- Blood Glucose Level: This is an important parameter for e.g. diabetes patients.
- Blood Pressure: A simple indicator for a person’s health.
- Oxygen Saturation: Measured indirectly, which means it cannot measure the amount of oxygen used by the user.
- Heart Rate: Increasingly important for top athletes.
- Step Count: An important parameter to measure daily fitness. Standardization of WBAN technologies is an important task of several research groups. Nowadays a number of technologies are used to operate within a WBAN:⁹
- ZigBee, an IEEE standard based protocol, enabling the use of low power wireless technology with less implementation effort.
- Bluetooth Smart, is the low power variant of the Bluetooth protocol, also an IEEE standard. The data rate is limited, but battery life make it suitable for medical applications in WBAN systems.
- NFC, a contactless communication technology used mainly by smart phones or tablets to gather in­formation of compatible sensors.

Bluetooth and ZigBee are mainly used in WPAN environments and adopted for applications operating using a WBAN. The IEEE 802.15.6 task group was founded to standardize WBAN technologies.¹⁰ The current standard proposes different frequency layers for data transmission: The Narrowband (NB) ranging from 400 MHz to 2.4 GHz, the Ultra Wideband (UWB) operating between 3.1 GHz and 11.2 GHz and the Human Body Communications (HBC) which uses 10 MHz to 50 MHz. Another technology is recently been added to the WBAN technology list: low-power WiFi, which is an adaptation of the IEEE 802.11 standard.¹¹,¹²

2.2 Wireless Personal Area Network

The WPAN has an indoor coverage up to 20 meters and is capable of high data rates up to 110 Mbps.¹³ The IEEE 802.11ah low-power WiFi protocol is currently under standardization, but other protocols like Radio Frequency Identification (RFID), ZigBee, Bluetooth or Near Field Communication (NFC) have already proved their concepts and are widely used in WPAN environments. They connect WBAN devices to higher level network architectures like WPAN or WLAN.¹⁴

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Figure 2.3: Interconnection of WPAN, source: Lanatà and Scilingo (2013)

Figure 2.3 shows an overview of a typical WPAN architecture. The WPAN is interconnecting devices and services from the WBAN. Body sensors and wearables of the WBAN are enabled to transmit their gathered information during their monitoring process to services or devices in WPAN for storage or further processing. The WPAN is focused on interconnecting personal equipment for portable and mobile communication.¹⁵

Such devices operating in a WPAN are:¹⁶

- Personal Computers (PCs) or Notebooks: Desktop PCs and notebooks are used for web surfing, home office, gaming and other applications. In conjunction with the WBAN devices they have mainly the role of a storage and control device, and they are able to bridge between various wired or wireless networks.

Personal Digital Assistants (PDAs) or Tablets: Nowadays a very important device to control entertain­ment systems, act within social networks and other mobile applications.

Mobile Phones: Maybe the only technical device spread across the whole world and de facto the standard device which every human being is using every single day. Most mobile phones have multi­ple wireless technologies implemented, a wireless cellular network technology and a WBAN / WPAN technology, like Bluetooth.

Printers: Many printers, both standalone and mobile models, are capable of accepting print jobs through WBAN technologies, like Bluetooth and NFC.

Speakers and Microphones: Bluetooth audio devices, such as hands-free equipment, are widely used for fitness and entertainment.

Consumer Electronics: Many remote controls are based on Bluetooth or other WPAN technologies to control electronic equipment and for streaming audio and video signals.

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Figure 2.4: Overview of WPAN standards, source: Jawad et al. (2014): p. 143

Nowadays the social networks are used to share arbitrary personal information of different media types around the world. These media consists of pictures taken by mobile phones, videos shot by action cams and many others. Those media streams have different requirements to WPAN technologies, such as bandwidth, data throughput and robustness.¹⁷

UWB and IEEE 802.11ah are exposed to provide high date rates up to 1 Gbps for streaming high definition video signals. Conversely, many other applications demand on lower data rates for transmission of monitoring and control commands, the domain where ZigBee is located. Figure 2.4 gives a summary of the IEEE WPAN technology standards.¹⁸

2.3 Wireless Local Area Network

The IEEE 802.11 working group is specialized on defining standards for the WLAN. The data rate is extended to 700 Mbps and the indoor coverage is around 50 meters, whereas the outdoor range is up to approximately 250 meters. The IEEE 802.11ad and IEEE 802.11ay groups are working on standardization of very fast 60 GHz communication offering data rates beyond 5 Gbps for IEEE 802.11ad respectively 100 Gbps for IEEE 802.11ay. Key requirements for WLAN technologies are:¹⁹

- Coexistence: WLANs operate within restricted Industrial, Scientific and Medical (ISM) bands and there­fore the WLAN technologies have to be able to coexist with other wireless networks operating at their bands.
- Throughput: To further increase the throughput of a WLAN system, the use of multiple antennas and an optimized or new wireless technology has to be discovered.
- Energy Efficiency: This is a very difficult requirement which is in contrast to throughput increase. Nonetheless is required to further decrease the energy consumption of the WLAN systems.

Backward Compatibility: Although it leads to inefficiency, a mechanism to provide backward compati­bility to former IEEE 802.11 standards should be provided.

Abbildung in dieser Leseprobe nicht enthalten

Figure 2.5: Typical WLAN scenario, source: devolo (2015)

Figure 2.5 shows a common indoor WLAN environment spread across multiple rooms. A smart TV streaming high definition video signals and media meta information from the Internet, a tablet receiving the latest news and social media updates, and a notebook running a fast-paced online game. The requirements to WLAN technologies are very diverse and span from low rate secure data transmission to very high rate data streaming.²⁰

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Table 2.1: Overview of IEEE 802.11 standards, adapted from: Bejarano, Knightly, and Park (2013): p. 85

Table 2.1 shows a comparison of the IEEE 802.11 standards. With IEEE 802.11ac the data rate massively increases. This is due to the modulation which is used by this standard and the ability to enable simultaneous multiple user connections.²¹

2.4 Wireless Campus Area Network

A WCAN is composed by connecting multiple WLAN across offices or throughout entire campus-like build­ings. Because of the geographical area used by campuses, the WCAN sometimes uses WMAN technologies to provide good wireless coverage over the campus area. The IEEE 802.11 and IEEE 802.16 standards are used for high data rate wireless networks with good indoor coverage. Using MIMO and MU-MIMO technol­ogy, the number of simultaneous connections of a wireless access point can be increased.²²

2.5 Wireless Metropolitan Area Network

The increasing demand for high data rate wireless transmissions in urban and sub-urban areas, requires new technologies. Covered by the IEEE 802.16 family of standards, the WMAN has a geographical coverage of operation of about 10 km. IEEE 802.16 based technologies are used to operate large-scale networks across cities.²³ The IEEE 802.16 standard is called Worldwide Interoperability for Microwave Access (WiMAX).²⁴ The WiMAX protocol family allows up to 64,000 simultaneous connections per access point. Two types of Broadband wireless access (BWA) services are currently available:²⁵

- Fixed Broadband: This type attempts to provide the same services as traditional wired broadband connections (e.g. Digital Subscriber Line (DSL) or cable modems).
- Mobile Broadband: Nomadicity and mobility are the features of this type of BWA services type. No-madicity is the ability to connect to the BWA base station from different locations within the coverage range of a BWA base station. Mobility describes the feature of keeping connections to the WMAN active while moving.

In 2011 the WiMAX Forum had stated a number of 583 WiMAX installations in over 150 countries world-wide.²⁶

2.6 Wireless Wide Area Network

The standards defining technologies for WWAN are typically based on cellular network topologies. A WWAN covers a geographical range of up to 10km. Technologies in WWAN are typical 2G and 3G systems:²⁷

- Global System for Mobile Communications (GSM) (2G): The GSM standard is based on Time Division Multiple Access (TDMA) and can achieve data rates up to 1 Mbps using Enhanced Data Rates for GSM Evolution (EDGE) technology.
- Universal Mobile Telecommunications System (UMTS) (3G): This standard is based in the Code Di­vision Multiple Access (CDMA) and provides up to 42 Mbps data transfer rates when Evolved High­Speed Packet Access (HSPA+) can be used.

The IEEE 802.16 standard defines a mobile broadband technology called Mobile WiMAX which is a fully compliant 3G system at data rates up to 80 Mbps.²⁸ The main difference to the fixed type WiMAX is the support for mobile devices, such as mobile phones, tablets or laptop computers. Embedded Mobile WiMAX solutions or Mobile WiMAX extension cards have to be used in conjunction with omni-directional antennas.²⁹

2.7 Wireless Regional Area Network

The IEEE 802.22 working group defines standards for cognitive radio-based PHY/MAC/air interfaces for the use in WRAN, which have a typical geographical coverage of 100km. Their target is to provide BWA with data rates up to 1.5 Mbps to areas with sparse Internet access. The spectrum of IEEE 802.22 is located in the TV Broadcasting 54 MHz to 862 MHz band.³⁰

[...]

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¹ Cf. International Telecommunication Union (2015).

² Cf. Kurkinen (2015).

³ Cf. Pahlavan and Krishnamurthy (2009): p. 1.

⁴ Cf. Ephremides (2013): pp. 49–52.

⁵ Cf. Latré et al. (2011): p. 6.

⁶ Cf. Movassaghi et al. (2014): p. 1660.

⁷ Cf. Kwak, S. Ullah, and N. Ullah (2010): p. 1.

⁸ Cf. Minoli (2013): pp. 69–70.

⁹ Cf. Minoli (2013): p. 71.

¹⁰ Cf. Latré et al. (2011): p. 10.

¹¹ Cf. Kwak, S. Ullah, and N. Ullah (2010).

¹² Cf. Minoli (2013): pp. 180–187.

¹³ Cf. Garg (2007): p. 676.

¹⁴ Cf. Lanatà and Scilingo (2013).

¹⁵ Cf. Garg (2007): pp. 654-704.

¹⁶ Cf. Garg (2007): pp. 654-704.

¹⁷ Cf. Garg (2007): pp. 654-704.

¹⁸ Cf. Garg (2007): p. 654.

¹⁹ Cf. Bellalta (2015).

²⁰ Cf. devolo (2015).

²¹ Cf. Bejarano, Knightly, and Park (2013): pp. 84–85.

²² Cf. Chen et al. (2009).

²³ Cf. Garg (2007): p. 713.

²⁴ Cf. Kirmse (2009): p. 1.

²⁵ Cf. Ephremides (2013): pp. 195–249.

²⁶ Cf. Ephremides (2013): p. 246.

²⁷ Cf. Ephremides (2013): pp. 402–403.

²⁸ Cf. Kirmse (2009): pp. 2-3.

²⁹ Cf. Kirmse (2009): pp. 3–4.

³⁰ Cf. Romme (2008): p. 2.