1 / 20

Chapter 3: Introduction of Wireless and Mobile Systems (Part II)

Chapter 3: Introduction of Wireless and Mobile Systems (Part II). Associate Prof. Yuh-Shyan Chen Dept. of Computer Science and Information Engineering National Chung-Cheng University. Outline. PCS WLL (Wireless Local Loop) LMDS (Local Multipoint Distribution System). PCS.

ilyssa
Download Presentation

Chapter 3: Introduction of Wireless and Mobile Systems (Part II)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Chapter 3:Introduction of Wireless and Mobile Systems (Part II) Associate Prof. Yuh-Shyan Chen Dept. of Computer Science and Information Engineering National Chung-Cheng University

  2. Outline • PCS • WLL (Wireless Local Loop) • LMDS (Local Multipoint Distribution System)

  3. PCS • Personal communication service • Developed out of the need for more capacity and design flexibility than that provided by the initial cellular systems • PCS • Narrowband service • Offers many enhanced data service • The data throughput remained at 9.6 kbit/s

  4. The Challenge of wideband PCS • Wideband PCS for offering high-speed data has not yet been deployed • The obvious issue • is coexistence with the current PCS system • The need for more base station due to reduced sensitivity cased by increased bandwidth • Is the offering of subscriber units that can act as dual band units

  5. PCS • PCS band was broken into A, B, C, D, E, and F blocks • A, B, C blocks involved a total of 30 MHz, while the D, E, and F blocks are allocated 10 MHz. • PCS license boundaries are defined as metropolitan trading areas (MTAs) and basic trading areas (BTAs). • The MTA has several BTAs within its geographic region

  6. PCS • There are a total of 93 MTAs and 487 BTAs in USA • All the frequency allocations are duplexed

  7. U.S. cellular spectrum chart

  8. PCS spectrum allocation

  9. WLL (Wireless Local Loop) • The WLL system, is different from the cellular or PCS systems in its application, which is fixed. • The fixed service is often referred to as a local multipoint distribution system (LMDS) or • A fixed wireless point-to-multipoint (FWPMP) system • In many case, WLL is the same as LMDS and FWPMP in its deployment and application

  10. WLL system • WLL is most applicable in areas where local phone service is not available or cost effective • WLL is a system that connects a subscriber to the PTSN or PTT (local telephone company) using a radio link as its transport medium instead of copper wires

  11. WLL Example

  12. More common types of WLL systems • Cellular • PCS • Cordless telephone (CT-2) • Digital European cordless telecommunication (DECT)

  13. WLL • For a developed country • WLL allows for use of a cordless phone as an extension of the house phone or private branch exchange (PBX), which is an added convenience • For a emerging country • Has areas without any access to a communication service • The use of WLL can create profound changes because it is quicker, easier, and less expensive to install than a regular landline system

  14. LMDS (Local multipoint distribution system) • The LMDS is a unique wireless access system whose purpose is to provide broadband access to multiple subscribers in the same geographic area. • The LMDS utilizes microwave radio as the fundamental transport medium and is not really a new technology

  15. LMDS • The LMDS system allows multiple users to access the same radio spectrum • The LMDS is a wireless system that employs cellular-like design and reuse with the exception that there is no handoff • Multiple subscribers (customers) surrounding an LMDS hub or base station

  16. Generic LMDS system

  17. LMDS • The LMDS is a point-to-multipoint system where multiple subscribers can access the same radio platform utilizing both a multiplexing method as well as queuing • Through overbooking • There are QoS issues and specific service delivery requirements

  18. LMDS • Provide vastly greater bandwidth requirements and service to a larger population than point-to-point system utilizing the same spectrum can

  19. The key differences between mobile systems and LMDS • The ubiquitous coverage is not required • Operator only provide service where the customers are actually located thereby maximizing the capital infrastructure effectiveness and minimizing operating expenses

  20. Example: Multiple Customer Location/Dwelling Unit

More Related