Interim Report
Wireless Repeater, Pico-BTS, WLAN
and W-PBX
Ian F. Akyildiz
Broadband and Wireless Networking Laboratory
School of Electrical and Computer Engineering
Georgia Institute of Technology
Atlanta, GA 30332
Email:
Tel: (404) 894-5141; Fax: (404) 894-7883
Executive Summary
Wireless technology is the solution to fulfill people’s desire to communicate from anywhere and at anytime. Compared to wire-line schemes, they have many advantages such tether-less communication, easy deployment, and low cost. The existing schemes of wireless local area communication can provide wireless services to end users to some extent of satisfaction. However, considering the ever-increasing demands for high speed, QoS, and global mobility of multimedia services, a new approach to wireless area communication is needed.
In order to succeed in the fierce competition of the Wireless market, it is imperative for a leader like KTICOM to adapt the recent most technologies in this area. The report concerns KTICOM and its attempts to develop a new approach to the next generation wireless communication in local areas. Typical existing local area wireless communication alternatives such as repeater, pico-BTS, WLAN, and WPABX are investigated individually. Such investigation mainly consists of technology analysis, target market forecast, technology development prospect analysis, network integration, service analysis, network design plan, network deployment scenarios, and network costs analysis.
The typical alternatives of wireless local area communications are also compared from the perspectives such as services, technical characteristics, costs, market, and network deployment scenarios.
To meet the goal of high speed, QoS guarantees, and global mobility of the next generation wireless communication networks, launching a project to develop new products for wireless local area communication is highly motivated. Such a project can be accomplished with solutions that have great potentials of market penetration capability.
Contents
Executive Summary
Introduction
1.Wireless Repeater
1.1.Overview
1.2.Technology, Standardization, Present Conditions of Repeaters
1.2.1.The Repeater Technology and Standards
1.2.2.Current Use of Repeaters and Industry Practices
1.2.3.Detailed System Analysis of the Repeater Technology
1.2.4.Interference to Repeaters
1.2.5.Environmental Issues
1.2.6.Major Suppliers of the Repeater Products
1.3.Repeater Types and Their Characteristics
1.4.Main Target Market Forecast
1.4.1.Current Market Segments and Their Penetration
1.4.2.A Forecast of the Target Markets and Estimated Market Size
1.5.Technology Development Prospect Analysis
1.6.Service Analysis
1.7.Network Design Plan Analysis
1.8.In-Building Network Design Alternatives Using the Repeater Technology
1.8.1.Coverage and Capacity Analysis as Part of the Network Design Process
1.9.Network Deployment Technology and Premise Network Security Plan
1.10.Network Deployment Scenarios
1.11.Network cost analysis
1.12.Conclusions
2.Pico-BTS
2.1.Overview
2.2.Technology and Standardization of pico-BTS
2.2.1.Characteristics and Advantages
2.2.2.Components and functionality
2.2.3.Current Progress of Pico-BTS
2.2.4.Standardization
2.2.5.Frequency Allocation
2.2.6.Power Management
2.2.7.Interference
2.2.8.Environmental Conditions
2.2.9.Major Suppliers and Products
2.3.Types of Pico-BTS
2.4.Main Target Market Forecast
2.4.1.Discussion of the Current Market Segments
2.4.2.A Forecast of the Target Markets and Estimated Market Size
2.5.Health and Safety
2.6.Technology Development Prospect Analysis
2.7.Service Analysis
2.7.1.Current Services (2.5G/3G)
2.7.2.Future Services
2.8.Network Design Plan Analysis
2.8.1.Distributed Antenna Approach
2.8.2.Distributed BTS Approach
2.9.Network Security Plan
2.10.Network Deployment Scenarios and Analysis
2.11.Network Cost Analysis
2.12.Conclusions
3.Wireless LAN
3.1.Overview
3.2.Technology, Standardization, Present Conditions of WLAN
3.2.1.The WLAN Technology and Standards
3.2.2.Current Use of WLAN and Industry Practices
3.2.3.Working Frequency, Typical Bandwidth, and Propagation Footprints of WLAN
3.2.4.Interference to WLANs
3.2.5.Environmental Issues
3.2.6.Major Suppliers of the WLAN Products
3.3.WLAN Types and Their Characteristics
3.4.Main Target Market Forecast
3.4.1.Current Market Segments and Their Market Penetration
3.4.2.A Forecast of the Target Markets and Estimated Market Size
3.5.Technology Development Prospect Analysis
3.6.Interworking/Integration with IMT-2000
3.7.Service Analysis
3.8.Network Design Plan Analysis
3.8.1.Description of Possible In-Building Network Design Alternatives using the WLAN Technology and possible external interference/interoperability
3.8.2.Coverage and Capacity Analysis as a part of Network Design Process
3.9.Network Deployment Technology and Premise Network Security Plan
3.10.Network Deployment Scenarios
3.11.Network Cost Analysis
3.11.1.Identification of the cost of various components involved in Wireless LAN setup
3.11.2.Analysis of the total Economics Involved in Deploying and Running such WLANs
3.12.Conclusions
4.Wireless PBX
4.1.Overview
4.2.Technology Analysis
4.2.1.Current Technology of WPBX
4.2.2.The Frequency Bands
4.2.3.Products by Leading Vendors
4.3.Characteristic Analysis
4.4.Main Target Market Deduction
4.4.1.Current Wireless PBX Market Segments
4.4.2.Market Forecast
4.5.Technology Development Prospect Analysis
4.6.Interworking / Integration Technology Analysis with IMT-2000
4.7.Service Analysis
4.8.Network Design Plan Analysis
4.8.1.Wireless Telephone Solution for Mobile Communication in the Workplace
4.8.2.Wireless Voice and Data Solutions Over Local Area Networks
4.9.Security
4.10.Network Deployment Scenarios
4.11.Network Cost Analysis
5.Comparison of Wireless Repeater and Pico-BTS
5.1.Comparative Service Analysis
5.2.Technical Characteristic Comparison and Analysis
5.2.1.Cost Comparison and Analysis
5.2.2.Comparison and Analysis of Main Markets and Network Deployment
6.Comparison of WLAN and WPBX
6.1.Comparative Service analysis
6.2.Technical characteristic (capacity and coverage) comparison and analysis
6.3.Cost Comparison
6.4.Markets and Network Deployment Comparison
7.Comparison of Pico-BTS and WLAN/WPBX
7.1.Comparative Service Analysis
7.2.Technical Characteristics Comparison and Analysis
7.3.Cost Comparison and Analysis
7.4.Comparisons and Analysis of Main Target Markets and Network Deployments
8.In-Building Deployment
8.1.Taking advantage of technological evolution and meeting customer demands
8.2.Network deployment scenario (Technology, Market, Architecture, Implementation Phases, schedule, Resource estimates)
8.2.1.Wireless PBX System deployment for corporate
8.2.2.WLAN internetworking with Wired Network
8.2.3.Unified 3G Wireless Network
8.2.4.Complementary Technologies of cdma2000 and 802.11
8.2.5.VPN security for Wireless Communication
8.2.6.HiperLAN/2 deployment for Corporate LAN
9.Conclusion
10.References
List of Figures
Figure 1. Wireless Repeater
Figure 2. Multiple transmitter networks
Figure 3. Multiple repeater networks
Figure 4. Wireless network within a single cell
Figure 5. Wireless Network using repeaters
Figure 6. Wireless repeater
Figure 7. Major components of a pico-BTS
Figure 8. IP radio access wireless network
Figure 9. In-building network
Figure 10. Distributed antenna
Figure 11. Distributed BTS
Figure 12. Alternative deployment with pico-BTSs
Figure 13. Protocol architecture of IEEE 802.11
Figure 14. Main operation procedures of the IEEE 802.11 MAC protocol
Figure 15. Scatter ad-hoc network of Bluetooth
Figure 16. Home networking based on HomeRF
Figure 17. The frame structure of SWAP
Figure 18. The frame structure of HiperLAN/2
Figure 19. WLAN market share of different segments
Figure 20. Interoperation between WLAN and 3G
Figure 21. Inter-system movement between WLAN and 3G
Figure 22. Ad-hoc WLAN
Figure 23. Client-server based WLAN
Figure 24. WPBX inter-operation with 3G systems
Figure 25. Link wireless telephone system architecture
Figure 26. NetLink wireless telephone system architecture
Figure 27. A wireless PBX system for small size corporate
Figure 28. WLAN 11Mbps system architecture
Figure 29. Unified 3G wireless network
Figure 30. VPN (IPSec) provides wireless network security
Figure 31. HiperLAN/2 used in a corporate network
List of Tables
Table I. Bandwidth and range of repeater from different suppliers
Table II. Comparison of products of major suppliers
Table III. Capital Cost of items in base stations and repeaters
Table IV. Comparison of CDMA pico-BTS products
Table V. Frequency bands for GSM base station systems
Table VI. Pico-BTS power classes
Table VII. Comparison between 802.11 and HiperLAN/2
Table VIII. Different Physical layers specified by IEEE 802.11
Table IX. Comparison of access point products of major suppliers
Table X. Comparison of LAN adapter products of major suppliers
Table XI. Comparison of LAN bridge products of major suppliers
Table XII. System parameters
Table XIII. Ranges possible for different data rates
Table XIV. Price comparison of different components of WLAN provided by major suppliers
Table XV. System capacity and area coverage
Table XVI. Cost comparison of WLAN and WPBX (unit: $)
Table XVII. Comparison of the features and services of pico-BTS and WLAN
Table XVIII. Comparison of the costs of pico-BTS, WLAN, and WPBX
Table XIX. Comparison of the markets of pico-BTS, WLAN, and WPBX
Introduction
Wireless technology is the solution to fulfill people’s desire to communicate from anywhere and at anytime. In order to succeed in the fierce competition of the wireless market, it is imperative for a company like KTICOM to adapt the recent most technologies in this area.
In this report, we have given detailed description about various alternative wireless technologies for KTICOM to keep its leading position in the future competitive wireless market. We introduce, analyze and compare each technology with respect to its technical advantages, forecasted markets, costs, and service capabilities.
In Chapter 1, we talk about Wireless Repeaters. Repeater is a bi-directional RF amplifier used to extend the reach of a base station. The standards and present use of Wireless Repeater are discussed in first section. Then, different types of wireless repeaters, market forecast, service analysis, network design, deployment scenarios, and network cost analysis are given detailed discussion in later sections.
Pico-BTS technology is investigated in Chapter 2. Pico-cellular solutions can offer higher capacity and better service quality inside buildings. Pico-cell base station systems are also suitable for shadowed areas and over-populated subscriber regions.
Section 1 and 2 discuss about technology and standards of Pico-BTS, followed by characteristics, advantages of different types of Pico-BTS. The subsequent sections present a detailed analysis of environmental effect, safety, expected market, network design and deployment of this technology.
Great details about Wireless LAN technologies are provided in Chapter 3. We start with an overview of various standards and types of Wireless LAN. Products from major suppliers are compared from different prospective. The issue of internetworking/integration of WLAN with IMT-2000 is presented too. The last few sections focus on various network deployments scenarios, network security plans and network cost analysis.
Chapter 4 is about Wireless PBX technology. A Private Automatic Branch eXchange (PABX or PBX) is a private telephone system within an enterprise that switches calls between the enterprise users on local lines automatically. Technology analysis, products from different vendors, main target market deduction, technology development prospect, internetworking with IMT-2000 and network design issues are all presented here.
Chapter 5 gives a detailed comparison of Wireless Repeater and Pico-BTS. WLAN and WPBX are compared in Chapter 6. Then, Chapter 7 compares Pico-BTS and WLAN/WPBX.
Chapter 9 presents different alternatives using the technologies mentioned above for in-building network design and deployment, followed by the final Conclusion.
1.Wireless Repeater
1.1.Overview
In a wireless communication system, a repeater consists of a radio receiver, an amplifier, a transmitter, an isolator, and two antennas [1]. The transmitter produces a signal on a frequency that differs from the received signal. This so-called frequency offset is necessary to prevent the strong transmitted signal from disabling the receiver. The isolator provides additional protection in this respect. A repeater, when strategically located on top of a high building or a mountain, can greatly enhance the performance of a wireless network by allowing communications over distances much greater than would be possible without it.
Traditionally, repeaters have simply been bi-directional RF amplifiers used to extend the reach of rural base stations, or to allow in-town base stations to cover areas shadowed by hills, valleys or buildings. Currently, a repeater is no longer just antennas, amplifiers and connecting cables [2]. The technology between the base station communication end of the system and the remote transmitters/receivers has evolved to a new, more capable level. For example, fiber optic inter-connection and adaptive interference cancellation (AIC) could be two additional features of wireless repeaters [2], [3], [4], [5]. The low loss characteristics of fiber allow a carrier to centralize base station radios and distribute radio signals to desired coverage areas where the size or cost of deploying additional base stations is not feasible. These repeaters are designed to enhance coverage and capacity in airports, malls, offices, campuses, industrial facilities, dense metropolitan areas, tunnels and highways. With the advantages of AIC, repeaters can have higher power, because AIC achieves much greater input/output isolation by canceling out the repeaters' own transmissions. Self-interference, which formerly limited the power and range of a repeater, is reduced by 30 dB or more [2].
Various standards, e.g., [6], [7], [8], [9], have been proposed for wireless repeaters in different application environments such as GSM, 3G systems, and wireless local area networks (WLAN). The objective of these standards is to make wireless repeaters fully compatible with CDMA, TDMA/IS-136 and PCS1900/GSM, and also forward-compatible with 3G/cdmaOne and W-CDMA.
Compared to base stations, wireless repeaters have many advantages:
- Extended transmission distance and increased coverage of wireless networks. This is the basic function of repeaters. By using wireless repeaters, the wireless signal can reach a longer distance. Some places such as hilly and shadowed areas, tunnel, in-building areas, and mine fields can be easily covered by repeaters.
- Reduced initial cost of wireless networks. Using repeaters instead of base stations can greatly reduce the cost. In some areas such as tunnel, shadowed areas, and highways, it is not necessary to deploy base stations because the overall traffic is not very high. Using repeaters, the backhaul traffic can also be more concentrated so that less backhaul links such as T1/E1 are needed [4].
- Easy deployment. Since repeaters are much simpler than base stations, they can be deployed easily and can be mounted anywhere. Moreover, when repeaters mounted on top of a tower, which is infeasible for base stations, can greatly improve the link budget [3].
- Improved capacity of existing wireless networks. Besides extending the coverage, repeaters can also improve capacity of wireless networks [2]. This feature is not obvious since no more base stations are added to the system. However, repeaters allow each base station to operate closer to its capacity by filling the "blind spots" in the coverage. By eliminating unusable capacity, more locations are served by the same number of base stations.
Some issues exist in wireless repeaters. One typical problem is the interference. For example, other radio communication devices in the same area can degrade the performance of wireless repeaters. Thus, certain rules must be used to provide reasonable protection against interference. Another typical issue is that harmful radiation of wireless repeaters must be avoided since repeaters are much closer to human beings in order to extend the coverage of base stations. Again, regulations of operating radio devices must be followed when manufacturing and using wireless repeaters. Moreover, deploying many towers and equipment of wireless repeaters around residential and in-building areas cannot always get user acceptance.
However, due to their advantages, wireless repeaters are being widely deployed. Companies such as Repeater Technologies have achieved great experience in developing and deploying wireless repeaters. Considering the quick evolution of wireless networks, new technologies still need to be developed in order to satisfy future requirements of wireless networks. First of all, the existing issues of wireless repeaters need to be resolved. Moreover, support of high speed and multimedia traffic is one of the challenging demands on future wireless repeaters. Also, a future wireless repeater must have the capability of being both backward-compatible with 2G and 3G wireless systems and forward-compatible with next generation wireless systems.
Wireless repeater is one of the key technologies for wireless communications. They will continue to be important components of wireless networks.
In this report, we give a comprehensive investigation of wireless repeater technologies. In Section 1.2, we first describe the functions, techniques, and standards of wireless repeaters. Then, current applications of repeaters, interference, and environmental issues are investigated. In the final part of this section, major suppliers of wireless repeaters are presented. In Section 1.3, repeater types are categorized. Characteristics of different types of repeaters are also addressed in this section. The target market forecast and technology development prospect are reported in Sections 1.4 and 1.5, respectively. Services provided by repeater technologies are presented in Section 1.6. Network design plan and network deployment technology based on wireless repeaters are analyzed in Sections 1.7 and 1.8, respectively. In Sections 1.9 and 1.10, the network deployment scenarios and cost analysis are presented.
1.2.Technology, Standardization, Present Conditions of Repeaters
1.2.1.The Repeater Technology and Standards
When the target receiver is beyond the range of the wireless transmitter, and is therefore incapable to receive transmissions directly, we need repeater links. On the other hand, deployment of repeaters can allow bases stations to support traffic in high usage areas, thus achieving a flexible capacity.
A repeater is a network device that repeats a signal from one port onto the other ports to which it is connected. Repeaters are low-level devices that amplify or regenerate weak signals, i.e., it merely passes along bits of data, even if a data frame is corrupt. A repeater does not filter or interpret anything; instead, it merely repeats a signal, passing all network traffic in all directions.
Wireless repeater, or wireless relay station, can extend the coverage/range of a base station, without the need to install additional wired base stations. It does not need an Ethernet connection. In instead, as shown in Figure 1, wireless repeater establishes a wireless communication link to one or more access points that are connected to an Ethernet LAN, while concurrently supporting wireless communications with stations within its local coverage area.