Which of the following spectrums are used by wireless networks? [choose all that apply]

1.4.1.2 WAVE

WAVE system intended to provide continuous, interoperable services for ITS. The focus of WAVE is about the communication between vehicles and vehicle to infrastructure. This service is acknowledged by the United States’ national ITS architecture and other research and industrial sectors. In order to specify the technologies associated with WAVE, the term DSRC is frequently used. The FCC has allocated bandwidth for DSRC system mobile services in ITS, and SAE J2735 has specified 5.9 GHz DSRC for the purpose of applications intended for the utilization of WAVE. With respect to vehicular networks, the WAVE systems currently visualize the design to meet the communication requirements. The IEEE WAVE standards documents, includes IEEE Std 1609.-2013, IEEE Std 1609-2010, IEEE Std 1609.-2010, IEEE P1609, IEEE Std 1609.11-2010, IEEE Std 1609.1, and IEEE Std 802.1-2012, respectively.

1.2 5G New Radio Access Technology

5G wireless access is envisioned to enable a networked society, where information can be accessed and shared anywhere and anytime, by anyone and anything [2]. 5G shall provide wireless connectivity for anything that can benefit from being connected. To enable a truly networked society, there are three major challenges:

A massive growth in the number of connected devices.

A massive growth in traffic volume.

A wide range of applications with diverse requirements and characteristics.

To address these challenges, 5G wireless access not only requires new functionalities but also substantially more spectrum and wider frequency bands.

Fig. 1.2 illustrates the operational frequency ranges of existing (2G, 3G, 4G) and future (5G) mobile communication systems. The current cellular systems operate below 6 GHz. A large amount of spectrum is available in the millimeter-wave frequency band (30–300 GHz); however, there is no commercial mobile communication system operating in the millimeter-wave frequencies today. 4G LTE is designed only for frequencies below 6 GHz. There are some local area networks and (mostly) indoor communication systems based on the IEEE 802.11ad and 802.15.3c standards that operate in the unlicensed 60 GHz band. IEEE 802.11ay, a follow-up of 802.11ad, is under development. 3GPP is currently developing a global standard for new radio access technology, 5G new radio (NR), which will operate in frequencies from below 1 GHz up to 100 GHz. 5G NR shall unleash new frequencies and new functionalities to support ever-growing human-centric and machine-centric applications.

The vision of 5G wireless access is shown in Fig. 1.3. 5G wireless access comprises both 5G NR and LTE evolution. LTE is continuously evolving to meet a growing part of the 5G requirements. The evolution of LTE towards 5G is referred to as the LTE Evolution [13]. LTE will operate below 6 GHz and NR will operate from sub-1 GHz up to 100 GHz. 5G NR is optimized for superior performance; it is not backwards compatible to LTE, meaning that the legacy LTE devices do not need to be able to access the 5G NR carrier. However, a tight integration of NR and LTE evolution will be required to efficiently aggregate NR and LTE traffic.

14.2.4 Fixed Wireless Access

Fixed wireless access (FWA) was briefly discussed in Section 2.1.6.1, and it has slightly different characteristics compared to mobile broadband (MBB), for example, often higher capacity demand, no mobility as the customer premises equipment (CPE) is installed in households, and better link quality. For example, FWA deployments with outdoor CPE often experience a high degree of line-of-sight propagation, leading to an improved and predictable link quality.

While an indoor CPE is comparable with an ordinary MBB terminal in terms of capabilities and performance, an outdoor rooftop mounted CPE performs significantly better by using a high-gain directional antenna and potentially higher output power. A correctly installed outdoor CPE has its directional antenna directed toward the antenna of the serving cell, which leads to a very stable link quality with lower path loss. This also creates a multiple-user multiple-input multiple-output (MU-MIMO) “friendly” environment as data packets are potentially larger and the signal-to-interference-and-noise ratio levels typically become so high that it is beneficial to share power between CPEs.

Note that FWA is not ‘a’ scenario like urban or suburban as discussed for MBB in previous subsections. FWA can obviously be deployed in different environments, for example, urban, suburban, or rural (Fig. 14.5).

7.7.5 Fixed Wireless Access

Fixed wireless access provides wireless communications between a fixed access point and multiple terminals. These systems were initially proposed to support interactive video service to the home, but the application emphasis has now shifted to providing high-speed data access (tens of Mbps) for homes and businesses. In the U.S. two frequency bands have been set aside for these systems: part of the 28-GHz spectrum is allocated for local distribution systems (local multipoint distribution systems or LMDS), and a band in the 2-GHz spectrum is allocated for metropolitan distribution systems (multichannel multipoint distribution services or MMDS). LMDS represents a quick means for new service providers to enter the already stiff competition among wireless and wireline broadband service providers. MMDS is a television and telecommunication delivery system with transmission ranges of 30 to 50 km. MMDS has the capability to deliver more than 100 digital video TV channels along with telephony and access to emerging interactive services such as the Internet. MMDS will mainly compete with existing cable and satellite systems.

Problems

1.1

Name the wireless access techniques used in 1G, 2G, and 3G wireless systems.

What are the three classes of wireless data networking?

Define the roles of WPAN technology in wireless data networking.

List the main features of 3G systems.

What is the role of GPRS in enhancing 2G GSM systems?

Show how CDMA IS-95 systems are moving to provide 3G services.

Show how 2G GSM systems are moving to achieve 3G services.

What are the data rate requirements for 3G systems?

Define IPWireless technology.

What are the goals of 4G systems?

Benefits for Property Owners

The advantages to deploying free wireless access are numerous. For a property owner, providing bandwidth is a way to “give back” to the community. Property owners can leverage their valuable rooftop locations for mounting antennas and other gear in order to provide a community resource for all to share.

In addition to the community benefit, property owners can also make their own properties (particularly rental locations) more attractive to potential tenants. Since a renter can avoid a monthly service fee for Internet access, the value of that particular property is greater then other locations where the renter would have to pay a monthly fee for bandwidth.

Deploying free wireless may (in certain circumstances) also be tax deductible for the property owner. Please consult with a tax professional for additional details.

Addressing Wireless Remote Access Design Considerations

5.

You are setting up wireless access to the network with two WAPs. You want to use a centralized authentication source for both access points. You have an existing IAS server on the network. Which of the following tasks are necessary to support wireless access? (Choose all that apply.)

Create a remote access policy.

Configure the WAPs to use RADIUS authentication.

Install a RADIUS server.

Add the WAPs as clients in the IAS server’s configuration.

You have configured a WAP using the EAP-TLS protocol. The WAP is connected to a LAN with a Windows Server 2003 server. Which of the following additional tasks may be necessary to ensure that wireless clients can connect? (Choose all that apply.)

Enable PPP authentication.

Issue computer certificates to clients.

Issue user certificates or smart cards to users.

Install and configure IAS.

1.1.2 Mobile Computing

The idea of mobile computing has only been around since the 1990s. Since then, mobile computing has evolved from two-way radios that use large antennas to communicate simple messages to today's mobile phones that can do almost everything a regular computer does. People cannot go to their local Starbucks and not see a laptop linked up to a hot-spot WiFi network. Two-way radios used by police officers were also considered mobile technology, but now, it means that human associated or operated mobile devices can connect wirelessly to the Internet or to a private network almost anywhere. As long as a person has one of the devices capable of wirelessly accessing the Internet, he/she is capable of participating in mobile computing. Today, smart phones and tablets are becoming the main approach to conveniently access the Internet; they have been developed for mobile computing and have taken over the wireless industry.

WiFi network is the most popular wireless access technology, supporting one-hop mobility between mobile devices and stationary access points as shown in Fig. 1.2. The portable and smart mobile devices have changed computing world dramatically, from huge machines that could not do much more than word processing to tiny handheld devices. It offers the opportunity to bring people together and give everyone access to a greater wealth of information and knowledge, and to share their knowledge with others. Peer-to-Peer (P2P) mobile ad hoc network has been promoted in military application scenarios; however, recent booming of Vehicle-to-Vehicle (V2V), communication solutions introduced P2P wireless networking solutions into civilian uses. Mobile computing can be generally defined as follows:

Mobile computing focuses on device mobility and context awareness considering networking and mobile resource/data access. Mobile computing applications usually rely on mobile devices to create, access, process, store, and communicate information without being constrained to a single location. Mobile computing usually considers similar types of mobile devices that offers many otherwise unattainable benefits to organizations that choose to integrate it into their fixed information system.

During the past three decades, mobile computing has expanded from being primarily technical to now also being about usability, usefulness, and user experience. This has led to the birth of the vibrant area of mobile interaction design at the intersection between mobile computing, social sciences, human-computer interaction, industrial design, and user experience design, among others. Mobile computing is a significant contributor to the pervasiveness of computing resources in modern western civilization. In concert with the proliferation of stationary and embedded computer technology throughout society, mobile devices such as cell phones and other handheld or wearable computing technologies have created a state of ubiquitous and pervasive computing where we are surrounded by more computational devices than people. Enabling us to orchestrate these devices to fit and serve our personal and working lives is a huge challenge for technology developers, and “as a consequence of pervasive computing, interaction design is poised to become one of the main liberal arts of the 21st century” [166].

From this angle, we can view mobile computing as the root of pervasive computing and even today's popular IoT technologies. Thus, it is important to understand the difference between mobile computing, pervasive computing, and IoT technologies. We can also view IoT applications as extensions of using mobile computing solutions, in which devices are heterogeneous (e.g., mobile vs. stationary, computer-grade smart phones vs. lightweight sensors), and they may belong to different administrative domains, where their computation and networking models are more distributed or decentralized, and the scale of the IoT system can be much larger than mobile computing application scenarios.

From the functionality and application per se, the history of mobile computing can be divided into a number of eras, or waves [166], each characterized by a particular technological focus, interaction design trends, and by leading to fundamental changes in the design and use of mobile devices. Thus, the history of mobile computing has, so far, entailed seven particularly important waves. Although not strictly sequential, they provide a good overview of the legacy on which current mobile computing research and design is built:

The era of focus on portability was about reducing the size of hardware to enable the creation of computers that could be physically moved around relatively easily.

Miniaturization was about creating new and significantly smaller mobile form factors that allowed the use of personal mobile devices while on the move.

Connectivity was about developing devices and applications that allowed users to be online and communicate via wireless data networks while on the move.

Convergence was about integrating emerging types of digital mobile devices, such as smart phones, music players, cameras, games, etc., into hybrid devices.

Divergence took an opposite approach to interaction design by promoting information appliances with specialized functionality rather than generalized ones.

The latest wave of applications is about developing matter and substance for use and consumption on mobile devices, and making access to this fun or functional interactive application content easy and enjoyable.

Finally, the emerging wave of digital ecosystems is about the larger wholes of pervasive and interrelated technologies that interactive mobile systems are increasingly becoming a part of.

3.4.3 VANET security mechanisms: IEEE 1609.2-2016 standard

The previous section discussed the different possible attacks. Some research on solutions against the different attacks listed, [MEJ 14] and [SUN 10], provide an interesting survey. In this section, IEEE 1609.2-2016 standard is discussed.

IEEE 1609.2-2016 (IEEE Standard for Wireless Access in Vehicular Environments and Security Services for Applications and Management Messages) proposes a standard with the following definition: “this standard defines secure message formats and processing for use by Wireless Access in Vehicular Environments (WAVE) devices, including methods to secure WAVE management messages and methods to secure application messages. It also describes administrative functions necessary to support the core security functions”. This standard is used in IEEE 1609.3-2016 for WAVE Service Announcement security and in SAE J2945/1-201603, On-Board System Requirements for V2V Safety Communications, for Basic Safety Message security. This standard provides the following requirements:

Secure protocol data unit (PDU) format for signed data and encrypted data: it provides payload, hash of external payload, provider service ID to indicate permissions with optional fields (generation time, expiry time, generation location, security management), reference to signing certificate and signature.

Certificate format for signing PDUs applications with pseudonymous (no identification of sender) and identifier: certificate contains permissions (service-specific permissions) and a provider service ID together with a signed secured PDU.

Certificate authorities (CA): all messages are signed by a certificate which is provided by a certificate authority in cascade with at least one certificate in the list known and trusted by a receiver.

Certificate revocation list (CRL) format that allows revoking or invalidating for different reasons (e.g. private key compromised, change in certificate).

Peer-to-peer certificate distribution to allow new certificates: this requirement is mandatory and added to the list of certificates with always the feature that one certificate is known in the list. Receiver should be able to build a cascade of certificates to a trusted and identified certificate.

To be a valid message, the receiver has to check that the signed secure PDU has verified that none of the certificates have been revoked, one certificate in the list is trusted, the signature is verified, the payload is consistent with the provider service ID and permissions and the message is relevant (recent, not expired, not a replay). The data are encrypted with symmetric key with a persistent public key. Concerning the exchange of certificate, it is based on asymmetric cryptography (public and private keys) that requires the establishment of a public key infrastructure (PKI). PKI provides several security services with a trusted CA with confidentially, authenticity, integrity and non-repudiation.

This standard is still in development and different research projects (e.g. Crash Avoidance Metrics Partnership) are providing input for its development.