Home > Articles > Networking > Wireless/High Speed/Optical

📄 Contents

  1. Overview
  2. System Description
  3. Historical Perspective
  4. Systems Engineering and the Role of the Systems Engineer
  • Print
  • + Share This
This chapter is from the book

This chapter is from the book

Systems Engineering and the Role of the Systems Engineer

Wireless communications, and communications in general, are specializations in the discipline of systems engineering. Our approach to the study of wireless communications from the perspective of a systems engineer is therefore a study in a specialized field of systems engineering. It is fitting, then, that we begin our study by discussing systems engineering at a general level.

Some type of system supports nearly every aspect of our daily life. Systems help us to travel anywhere on the Earth (and beyond), create memos, solve complex problems, store and retrieve vast arrays of information, cook our food, heat and light our homes, entertain ourselves and our friends, and of course communicate with each other. There is no universally accepted standard definition of a "system," but the purposes of this discussion are served by the working definition: A system is any collection of elements or subsystems that operate interdependently to perform some specified function or functions.

An automobile, an airplane, a personal computer, a home, a television or radio, an ordinary telephone, and a microwave oven are all common examples of systems. But at a lower level, an automobile engine or transmission, an airplane's hydraulic system, a computer chip or microprocessor, a home air-conditioning or heating unit, or the video circuitry of a television or audio circuitry of a radio are also systems by definition. Depending on the context of discussion, a system may often be referred to as a subsystem, since it may perform only a few of the intended or auxiliary functions of the overall system of which it is a part. For example, an automobile is a system that conveys passengers and/or objects to arbitrary geographic locations. Its subsystems are the engine, transmission, braking system, steering system, chassis, dashboard, and so on, all of which are necessary for an automobile to perform the functions we have come to expect. Likewise, an engine is a collection of other subsystems such as the ignition system, fuel system, and emission control system. At some level the terms system and subsystem become less relevant. For example, a passive circuit may be considered a system, but considering resistors, capacitors, and inductors as subsystems has little relevance. In such instances we may choose to use the term component or element.

In the previous sections we introduced a simplified block diagram for a generic wireless system. Each block may be considered a subsystem of the overall system. Furthermore, each block performs some direct or auxiliary function needed to meet the general requirements of the system application. Regardless of the intended wireless application, the designs of the various blocks and their functions are founded on principles derived from distinct specialty areas. To identify a few of these specialty areas:

  • Antennas and electromagnetic wave propagation
  • Microwave circuit theory and techniques
  • Signals, systems, and signal processing
  • Noise and random processes
  • Statistical nature of the environment and its effects on a propagating signal
  • Communication theory
  • Traffic theory
  • Switching and networking theory

Depending on complexity and scale, the design and development of a system usually require knowledge and professional expertise in a number of distinctly different disciplines. For example, the development of large-scale wireless systems, such as personal communication systems or advanced radar systems, requires the participation of specialists in such diverse disciplines as

  • Antenna design
  • RF propagation and radio environment modeling
  • Microwave circuit design
  • Transmitter design
  • Low-noise amplifier (LNA) design
  • Modulator/demodulator (modem) design
  • Digital circuit/system design
  • Signal processing
  • Real-time, non-real-time, and embedded software development
  • Power systems and power management
  • Switching, networking, and transmission
  • Mechanical structures and packaging
  • Human factors engineering
  • Manufacturing engineering
  • Reliability and quality engineering
  • And, last but not least, systems engineering

Successful development companies usually have processes (sequences of well-defined steps and procedures) and information systems that allow development teams to work and communicate effectively; track progress; manage schedule, budget, and other resources; control changes; and maintain and improve product quality. Highly successful companies also review their processes, constantly seeking ways to reduce development costs and schedule time while improving product quality, customer satisfaction, and cost competitiveness. In fact, process engineering and improvement is an important area of specialization. A strong and continuously improving development process is often vital to a company's ability to compete in a given market.

Development processes may vary among companies, but they all possess common phases of particular emphasis, for example,

  • Product/system definition
  • Design/development
  • Integration and system test
  • Manufacture
  • Product life-cycle management

The specific activities in each phase may vary significantly, and many of the phases may, and often do, run concurrently.

One of the most important factors contributing to the successful development of a system is a complete, well-directed, and stable product definition. The product definition, sometimes called "functional product requirements" (FPR), is usually developed by a marketing or market research organization in concert with members of the technical development community, especially systems engineering. In addition to specifying the required attributes of the system from a customer perspective, an FPR also defines all the information necessary to ensure a viable financial return for the investors, including cost to manufacture the product, time to market, development budget, projected manufacturing ramp-up and life-cycle volumes, key competitive attributes, and so forth.

The design and development phase of any system usually begins with a system design. It is one of the most important products of a systems-engineering effort. A system design consists of all the requirements, specifications, algorithms, and parameters that a development team uses to design and develop the hardware and software necessary to implement and manufacture a product in accordance with an agreed-upon product definition. System-level documentation may include

  • System-level requirements—a high-level technical document that translates the needs expressed from a customer perspective into technical constraints on system functions, performance, testing, and manufacture
  • System architecture—a specification that defines all of the parameters and subsystem functions necessary to ensure interoperability among subsystems and meet system requirements, including distribution of system-level functions among the subsystems, definition of subsystem interfaces, and specification of system-level controls
  • Supporting analyses—appropriate documentation of all analyses, simulations, experimentation, trade-off studies, and so on, that support the choice of key technical parameters and predict and/or verify system-level performance

As it relates to a system design, the responsibilities of a systems engineer are to

  • Translate customer-level functional requirements into technical specifications at a system level
  • Develop a system architecture and determine specific parameters to ensure that the system will meet the desired level of functionality and performance within specified constraints
  • Perform trade-off analyses among the system elements to ensure that the implementation requirements can be met within the specified constraints and technology limitations
  • Develop and negotiate specific requirements for each of the subsystems based on analysis, modeling, experimentation, and simulation

These functions are the focus of this text and are the basis for many other functions that systems engineers perform. These other functions might include

  • Interacting with potential customers
  • Developing human-interface specifications
  • Developing plans, methods, and criteria for system integration and verification
  • Interfacing with government and legal entities
  • Specifying deployment, maintenance, and operations procedures
  • Competitive analysis
  • Supporting regulatory and standards development

Depending on the complexity of the system being developed, a team of systems engineers, each of whom has a particular area of expertise, may be required to fully perform all of the systems-engineering functions of a development.

Problem Statement

This text develops the major systems aspects of personal communication systems while demonstrating the application of relevant theory and principles and introducing students to some of the real-world aspects of the wireless systems-engineering profession. It is fitting, therefore, that the subject matter be presented in the context of a solution to a general systems-engineering problem. To be specific, we seek to design a wireless telecommunication system that will

  • Support the communication of information of various types, including speech, text, data, images, and video, in urban, suburban, and rural environments and with quality approximating that of wired communications
  • Be capable of expanding in geographic coverage
  • Allow for virtually limitless growth in the number of users
  • Support endpoints that are not geographically fixed and, in fact, may be moving at vehicular speeds

Many of the attributes of this system, as stated previously, were in fact the major objectives underlying the development of the very first cellular mobile telephone systems. Our discussions of principles and concepts are presented as motivation for solving this systems-engineering problem in particular. In view of the continued advances in digital technologies and the directions of modern communication systems, our emphasis will be on digital wireless communications, although many of the principles apply to both analog and digital systems.

Since the advent of the first mobile phone systems, the meanings of some commonly used terms have become blurred by marketing and advertising efforts to provide some level of distinction between early first and later generations of systems. Specifically, the terms cellular and PCS are often used to identify the cellular frequency (850 MHz) or personal communication systems (or services) (1.9 GHz) frequency bands. The term cellular, however, originally referred to the technology underlying nearly all of the systems that may be classified as personal communication systems. We will endeavor to ensure that the meaning is always clear in context; however, it is important to recognize that most modern systems are capable of operating in either band.

  • + Share This
  • 🔖 Save To Your Account

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.

Overview


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information


To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020