POSITIONING OF DECT. Positioning of DECT in relation to other radio access technologies. Version 1, 30 June page 1 -

Transcription

1 POSITIONING OF DECT Positioning of DECT in relation to other radio access technologies Version 1, 30 June page 1 -

2 Table of content 1 Abstract with short Summary DECT Local Area applications Personal Area applications Telemetry, control and supervision (data only) applications Bluetooth WLAN Cellular technologies Summary on the positioning of DECT Residential applications Enterprise applications Combined voice and data applications Personal Area applications Public applications Data only telemetry and control application Introduction to DECT A general Access Technology Interoperability Profiles page 2 -

3 2.3 An IMT-2000 family member Introduction to DECT applications No frequency planning Guaranteed quality Residential and small office applications Office multi-cell applications Voice and Data services Ad hoc networking and cord replacement applications Direct Portable to Portable communications Public pedestrian and WLL applications Public Pedestrian applications Wireless Local Loop, WLL, applications Wireless relay station, WRS Positioning of wireless technologies for home (SOHO) applications Position of wireless technologies for residential access of voice and data services Residential telephony voice services Europe The US and Canada Japan Other countries Residential data services Europe page 3 -

4 4.3.2 The US and Canada and Japan Other countries Positioning of wireless technologies for enterprise (office) applications Wireless indoor services Wireless office applications are not mass market drivers General replacement Partial replacement/complement Combination of cellular indoor and wide area mobility Sizes of wireless systems in enterprises and related costs Size distribution of wireless systems Costs of wireless enterprise systems Enterprise main wireless options Summary present main applications and potential evolution References Annex 1 Unlicensed Radio Technology Overview A1.1 DECT A1.2 DECT in the 2.4 GHz ISM band for the US market A1.3 European 900 MHz residential systems, analogue CEPT CT1 and digital CT A1.4 US Analogue 40 MHz residential systems (CT0) A1.5 US cordless systems on the 900 MHz ISM band, US-CT900 and DECT A1.6 US and Canada Unlicensed PCS devices in the MHz band page 4 -

5 A1.7 US Home-RF cordless systems on the 2.4 GHz ISM band A1.8 Bluetooth A1.9 IEEE b WLANs in the 2.4 GHz ISM band A1.10 Hiperlan 2 and IEEE a/e WLANs on the 5 GHz bands A.1.11 Japan; PHS and analogue types A.1.12 Summary of main applications for the different wireless technologies Annex 2 Cost A2.1 Medium and large size offices (>20 employees) A2.1.1 Cost for data access A2.2 Small size offices (<20 employees) A.2.3 Single cell residential systems Annex 3 The inherent capabilities/limitations of different technologies A3.1 The difference between a protected an unprotected spectrum band A3.2 IEEE b WLAN interference to Bluetooth A3.2.1 Summary on Bluetooth ranges A3.3 Comparing Bluetooth link budget with DECT, CT 1 and CT A3.3.1 Bluetooth link budget assessment A3.3.2 Comparison with major cordless technologies A3.3.3 Conclusion on link budget difference Annex 4 Range calculations and number of users per base station/ap A4.1 Comparing raw link budget range page 5 -

6 A4.2 Comparing absolute link budget and range A4.2 Number of users per base station / access point (AP) Annex 5 Technology and market hypes Annex 6 DECT as a world wide access technology Annex 7 Combined voice and data services in one DECT radio A7.1 Combined speech and data services A7.3 Conclusion page 6 -

7 1 Abstract with short Summary This document positions DECT, Digital Enhanced Cordless Telecommunications, in relation to other short and medium range technologies for wireless voice and/or data access. This document attempts to peal off the marketing hype from various wireless technologies and apply a matured view on their main applications. The figure below shows a typical history path from first idea to development excitement, marketing hype and finally maturity. A technology for product applications X and Y This technology is suitable for everything! Marketing Hype Understand that It is not suitable for everything! Recognise that main applications from technical and market perspective are X and Y The Idea Development Excitement History Maturity Figure 1-1. Positioning of a technology, going from idea via marketing hype to maturity. Note: Examples of idea, marketing hypes and maturity statements for Cellular technologies, Bluetooth, WLAN, and DECT are found in Annex 5. The table below gives a summary of main application areas for DECT, Bluetooth, WLAN and cellular technologies. Typical hype statements have been pealed off. Bold technology names in the table below indicate present main applications. All technologies below provide, according to their standards, higher bit rates than indicated. Indicated bit rates are though realistic for typical main product applications. A mass market technology is in this context defined as shipment of > 20M units /year. - page 7 -

8 Positioning of Personal Area & Local Area Wide Area* wireless access TECHNOLOGIES for voice and data other Short Cord Replacement applications Single cell Multi-pico-cell with handover (Indoor & outdoor coverage) Voice & voice band data (<9.6, 32 or 64kbps) Bluetooth DECT DECT DECT Cellular 2G+/ 3G technologies Best Effort Data Bluetooth b DECT Cellular 2G+/3G < Mbps DECT DECT technologies Best Effort Data > 1 Mbps b b Real Time Streaming Data < Mbps DECT Bluetooth DECT DECT Cellular 3G technologies Real Time Streaming Data > 1 Mbps (5 GHz WLAN) (5 GHz WLAN) *) Cellular technologies provide indoor radio coverage mainly from outdoor cells. Table 1-1. Positioning of DECT in relation to other main wireless access technologies for voice and data services. It is important to note a very basic difference between the unlicensed wireless technologies (DECT, WLAN, Bluetooth) and cellular technologies. The unlicensed wireless technologies are access technologies, which mainly just transfer or map the services of the interfaced local (PABX, or LAN) or public (PSTN, ISDN, GSM, UMTS, Internet) networks to a wireless terminal. But the cellular systems are public networks with dedicated own services. Furthermore, the unlicensed standards and products have been optimised for low cost local (indoor) short range access. The spectrum is free of change and is typically not a scarce resource. These products compete in environments where there normally already exists better - page 8 -

9 lower cost wired alternatives (PSTN/PABX telephony and LAN for internet and intranet access). This very much puts a natural limitation to the market for wireless access in residents and enterprises, and forces the wired access costs to be in parity with the existing wired alternatives. On the other hand, cellular standards and systems support own network services and are optimised for wide area coverage and vehicular speeds. The spectrum is a very expensive and scarce resource. But, there is no good wired low cost alternative to the cellular wide area services. This provides very good business cases for the cellular wide area concept, but not as dedicated indoor infrastructure systems for local wireless access. Such an indoor infrastructure is much more expensive ( times) than an unlicensed infrastructure, and production cost for unlicensed terminals is also normally less (2-4 times) than cellular terminals. This leads to two important observations: A. The cellular market is much larger than the indoor unlicensed access market. B. Cellular indoor access will mainly be provided as cellular core network services from the public outdoor macro base station infrastructure, and unlicensed access will be provided as low cost indoor high capacity infrastructures mapping the local or public wired network services. Below main characteristics of DECT and other main wireless technologies are summarised. 1.1 DECT DECT is a mass market technology operating on a protected unlicensed spectrum. DECT spectrum is available in most countries of the world, however in the US and Canada as the DECT derivative PWT (see section A1.6). Since May 2002, standard DECT is allowed to be applied in the US also on the unprotected 900 MHz, 2.4 MHz and 5.7 MHz ISM bands (see section A1.2). More than 100 companies are involved in DECT product development Local Area applications DECT is the dominating and most proper technology for voice services (including mobility with seamless handover) for the local area. DECT is also very suitable for real time and best effort data services below 1Mbps, although it is expected that b best effort services will dominate the local area wireless data market. The strength for DECT is the unique capability to effectively combine high quality voice - page 9 -

10 telephony with data services in the same base stations. This strength has not yet been fully utilised by existing products. See Annex Personal Area applications DECT is also very suitable for personal area, PAN, and short range cord replacement applications, although it is expected that Bluetooth (PAN) will dominate this market together with b. The strength for DECT is the low cost (equal to Bluetooth technology cost) in combination with the unique capability to effectively combine high quality voice telephony with data services. This property is related to the unique DECT channel access mechanisms in combination with a protected spectrum. The spectrum issue (previous lack of DECT spectrum in the US) was the main reason why Bluetooth was developed. Else DECT would be a more suitable choice. Standard DECT can now be deployed in the US 900 MHz, 2.4 GHz and 5.7 GHz ISM bands, which could increase the attractiveness for DECT personal area and short cord replacement applications. See Annex Telemetry, control and supervision (data only) applications Over the last years we have seen a substantial market increase for different kinds of telemetry, control and supervision applications. These DECT applications solve control and supervision needs in a variety of products and systems. DECT provides a commodity technology with a protected and secure wireless link, that many other wireless link alternatives lack. 1.2 Bluetooth Bluetooth is expected to become a mass market technology during year Bluetooth operates on the unprotected world wide 2,4 GHz ISM band. The main mass market driver is the integration into cellular handsets as a PAN enabler. This main application will spread into other short cord replacement applications, mainly for best effort data services below 1 Mbps. The unprotected 2.4 GHz ISM band spectrum and related channel access mechanisms limit the feasibility for voice and other real time services. 1.3 WLAN WLAN is expected to become a mass market technology during year 2003 or page 10 -

11 The presently dominating WLAN technology is IEEE b operating on the same unprotected world wide 2,4 GHz ISM band as Bluetooth. IEEE b provides best effort data services with user bit rates up to about 7 Mbps. The main mass market driver is the integration into PCs as wireless LAN access enabler. This main application will spread into other best effort data cord replacement applications. The unprotected 2.4 GHz ISM band spectrum and related channel access mechanisms makes it unfeasible for voice and other real time services. WLAN products are also coming on the 5 GHz band, where several 100s of MHz will become available. Bit rates up to about 30 Mbps will be supported. This spectrum is not an ISM band, but still unprotected. Even if quality of service, QoS, cannot be supported in some absolute sense, the fact that the spectrum is so large, makes it easier to make proprietary solutions for QoS, and use different parts of the spectrum for adjacent and overlapping systems. Main applications will be for best effort data services, but the possibility to support real time services (e.g. residential wireless video transmission) will be better in the 5 GHz band than in the 2.4 GHz ISM band. 2.4 GHz WLANs (802.11b) are supposed to dominate the WLAN market for the next 3-5 years. 1.4 Cellular technologies Cellular is since many years a well established world wide mass market technology. It operates on protected licensed spectrum. The large cellular market is split by different standards being favoured in different regions. GSM is the dominating standard. The protected spectrum makes cellular technologies suitable for voice and other real time services, but the scarce expensive spectrum limits the bit rates of data services to Mbps. The cellular standards and systems are optimised for wide area coverage and vehicular speeds. Indoor coverage is mainly provided from outdoor cells. The indoor coverage is sometimes marginal and the indoor capacity may be limited dependent on the local macro cell density. The provided services are the cellular core network services, sometimes amplified with centralised VPN or Centrex services. Large public hot spots as large airports and large shopping centres are often provided with cellular multi-operator/multi-standard distributed antenna indoor infrastructures. Indoor pico cell infrastructures have a very marginal market. - page 11 -

12 1.5 Summary on the positioning of DECT DECT is a low cost high capacity wireless access mass market technology, available in most countries of the world. DECT has a protected spectrum and unique instant dynamic channel selection processes that provide coexistence of high quality real time (speech, streaming etc.) connections in environments of unco-ordinated DECT system installations. Data services up to >3 Mbps are standardised Residential applications DECT will continue to be the dominant mass market cordless residential technology for several years. DECT provides mobility within the home including the garden. There is thus a driver for local mobility. This local mobility driver has created the large DECT residential market. 2.4 GHz ISM band technologies (e.g. Bluetooth and WLAN) are, due to limited feasibility for voice and other real time services, not expected to become major competitors to DECT. There is hardly any competition from e.g. cellular phones. When a cellular private phone is bought, it is normally because there is some kind of driver for wide area mobility. Such a phone can of course be used for local mobility, but the service cost is too high (and speech quality and coverage sometimes too low) to compete with DECT for local access. Thus cellular private phones are normally not used to replace the fixed telephone service, and the service is too expensive for local access compared to an unlicensed technology as DECT Enterprise applications DECT will continue to be the dominant unlicensed enterprise voice mobility technology for several years. 2.4 GHz ISM band technologies like Bluetooth and WLAN are not suitable for voice mobility applications and are no real alternatives to DECT. In the US and Canada DECT enterprise applications have so far consisted of the DECT derivative PWT (see section A1.6). With the new US rules allowing standard DECT in the US 900 MHz, 2.4 GHz and 5.7 GHz ISM bands, we could expect a boast of standard DECT enterprise applications within the MHz band. This band contains no microwave ovens and no (nomadic) Bluetooth or WLAN devices. It contains mainly cordless phones, but such will not be installed in the same office as an enterprise DECT system. Thus the band MHz could become more or less locally protected from interference from incompatible systems. - page 12 -

13 Cellular phones are also used for local enterprise voice mobility, but they do not replace DECT. About 10% of employees have a cellular subscription paid by the company. Those phones are provided because a need for wide area mobility. They are not bought to provide local mobility. Once they are bought for wide area access, of course they can also be used for local mobility using the PABX call transfer feature (unless prohibited/limited by high cost for local calls and/or marginal coverage). Cellular does not replace fixed access in offices, but is bought for wide area access. Wide area access is only needed for a fraction of employees. There is hardly any market for enterprise cellular local access infrastructures. It costs too much, the wired alternatives provide better quality and performance, the need for local mobility is limited to a fraction of the employees and the local only mobility needs are better served at much lower cost by unlicensed access technologies like DECT and WLAN. About 10 % of PABX extensions have DECT mobility access. This market is because of the need for local mobility. The reason that there is not a higher penetration (in spite of costs in parity with the fixed access) is mainly because the enterprise need for local mobility is limited, and that the wired phone service is very good and convenient. Thus basically, not even DECT is bought to replace fixed access, it is a complement for those who really need the local mobility (including messaging, alarms, group calls and supervision). The perception that cellular has replaced DECT for enterprise local mobility access is not unusual. This is however not true, it is just that the need for mobility in offices is limited, which limits the visibility Combined voice and data applications One strength for DECT is the unique capability to effectively combine high quality voice telephony and high quality medium rate data services in the same base stations. This strength has not yet been fully utilised by existing products. See Annex 7. The presently dominating DECT speech service and low rate data services, will to an increasing extent be bundled with cost effective medium rate data services up to about 1 Mbps or more Personal Area applications DECT is also as technology very suitable for Personal Area Networks, PAN, and short range cord replacement applications. It is however uncertain if DECT PAN applications will ever pass a niche market position, due to earlier lack of easily accessible US spectrum and the - page 13 -

14 momentum for Bluetooth, having PAN and short range cord replacement as main applications. Standard DECT can now be deployed in the US 900 MHz, 2.4 GHz and 5.7 GHz ISM bands, which could increase the attractiveness for DECT personal area and short cord replacement applications. See however Annex Public applications DECT is also technically well suited for public pedestrian and WLL applications. Interoperability profile standards are available for both applications. There are possibilities to have a common infrastructure for pedestrian and WLL applications. However, the general availability of subsidised cellular phones combined with low cost and low commitment subscription alternatives, limit the business opportunities for DECT public pedestrian implementations. The WLL applications support voice telephony, ISDN and packet data internet user data access up to a few hundreds of kbps. This suits needs in developing countries. There are about 1.5 M DECT WLL subscriber lines in operation. Sales seem however presently to be limited Data only telemetry and control application Over the last years we have seen a substantial market increase for different kinds of telemetry, control and supervision applications. These DECT applications solve control and supervision needs in a variety of products and systems. DECT provides a commodity technology with a protected and secure wireless link, that many other wireless link alternatives lack. - page 14 -

15 2 Introduction to DECT DECT: Worldwide Standard adopted in more than 115 countries ISM band DECT & PWT (DECT based) America: 23 countries Europe: 45 countries Africa: 26 countries Asia-Pacific: 22 countries Figure 2-1. DECT is a world wide standard. DECT is a world wide standard. Spectrum is available in almost every country. The spectrum allocation is MHz in Europe and in most other countries. China has allocated MHz, and several Latin American countries MHz. In the US and Canada spectrum is available in MHz for the DECT derivative PWT. PWT uses the DECT frame and bit structure, MAC, DLC etc, but has a different modulation and carrier spacing to meet local regulatory requirements. In the US and Canada standard DECT may since May 2002 be implemented in the MHz, MHz and MHz Part 15 (ISM) bands. Not least the 900 MHz band is expected to become widely used for DECT residential and enterprise products in the US and Canada. DECT in the 900 MHz band is called DECT900 in this document. A frequency hopping DECT derivative operating on the 2.4 GHz ISM band is also available. It will be will be less interesting in the US with the new Part 15 rules, but it is still useful in Japan. - page 15 -

16 Total Annual Sales Shipped units (mio) Voice and Data Figure 2-2. Total annual sales of DECT units DECT is a mass market technology. See the chart above on annual sales. The residential applications dominate. Second comes the enterprise market with about 4-6 M units/year for single cell systems and about 1 M units/year for multi-cell systems. Third comes DECT Wireless Local Loop ( WLL) systems having about 1.5 M subscriber lines in operation. 2.1 A general Access Technology DECT is a general radio access technology, that is used by many different applications to connect to different telecommunication networks. It is essential to see the implications of the difference between an access technology and cellular radio systems like GSM and UMTS. In these cellular radio systems the whole network is part of the specification and a mobile unit can only access the unique network that is part of the cellular radio system. DECT as a general access technology provides a comprehensive set of protocols, which provide the flexibility to interwork between numerous different applications and different private and public networks, including UMTS and IP networks. - page 16 -

17 2.2 Interoperability Profiles Besides the network interfaces, the DECT standard defines a number of air interface interworking profiles. An air interface interworking profile standard allows interworking between a network from one manufacturer and terminals from other manufacturers. The first was the Generic Access Profile, GAP, for the basic telephony teleservice. GAP which defines the minimum interoperability requirements including mobility management and security features. The basic interoperability service for packet data is DPRS. The DECT standardisation include several other air interface interoperability profile standards, as well as optional higher level modulation schemes. These optional modulation schemes increases the user data rate from maximum 845 kbps to > 3 Mbps. Future Outlook : DECT Migration Path High-Level Modulation IMT2000 (IMT/FT) GAP DPRS up to >3 Mbps Data Communication kbps Time Figure 2-3. DECT evolution path. 2.3 An IMT-2000 family member DECT is also an IMT-2000 family member, denoted IMT-FT. IMT-FT (DECT) is the only IMT member that is optimised for private uncoordinated use. DECT already operates within the IMT-2000 spectrum with 3G service capabilities. DECT/UMTS interworking standards are ready. Being an IMT-2000 member secures spectrum as well as past and future investments in DECT. - page 17 -

18 3 Introduction to DECT applications As mentioned above, DECT is a general radio access technology for wireless telecommunications able to be connected to a variety of different networks. 3.1 No frequency planning Guaranteed quality The mandatory and unique Instant Dynamic Channel Selection, idcs, messages and procedures provide effective co-existence of unco-ordinated private and public systems on the common designated DECT frequency band and avoids any need for traditional frequency planning. Each device has access to all channels (time/frequency combinations). When a connection is needed, the channel is selected, that at that instant and at that locality, is least interfered of all the common access channels. This avoids any need for traditional frequency planning, and greatly simplifies the installations. This procedure also provides higher and higher capacity by closer and closer base station installation, while maintaining a high radio link quality. Not needing to split the spectrum resource between different services or users gives a very efficient use of the allocated spectrum. DECT has become a high capacity mass market digital technology for cell radii ranging from a few meters to several kilometres, depending on application and environment. It provides telephony quality voice services and a broad range of data services, including ISDN and Internet packet data access. A more comprehensive overview of the DECT standardisation is provided by the ETSI technical report TR A High Level Guide to the DECT Standardization. This section gives examples of typical applications and services provided by DECT products. - page 18 -

19 3.1 Residential and small office applications Home/SOHO Scenario DPRS ISDN-Basic Rate Access Residential systems is the largest DECT application area. The system in the figure above uses basic rate ISDN access. The fixed access unit provides tethered connections for telephone, fax and PC, as well as wireless telephone and wireless PC access. Simpler systems provide PSTN access with cordless handsets only. Typically 6-10 handsets are supported for external and intercom access. More advanced systems for PSTN access are complemented with voice band or ASDL modems for wireless data access to PCs. The coverage may also be extended by the DECT wireless relay station, WRS, which is a wireless base station for adding cells (with handover functionality) to the system without need for wires nor radio node controller. See below. Single cell systems, with or without coverage extension WRS units, have a large market also in small enterprises. 3.2 Office multi-cell applications Enterprise mobility applications including mobility with seamless handover is another main application area for DECT. DECT is a necessity for PABX sales in Europe, and is expected to - page 19 -

20 be so for several years. In Europe and other DECT -countries all major PABXs have integrated DECT access with special line cards for interfacing multiple base stations. There is no separate radio exchange or base station controller, and the cost/extension becomes similar for wired extensions and DECT wireless extensions. This makes the DECT access very cost efficient. System sizes span from DECT extensions, but most systems are rather small, users, because most local enterprise sites are small. Large Enterprise Scenario Base Stations Supports up to 20,000 users Requires cordless phones supporting the DECT CAP protocol Requires synchronisation ring between LIM s The DECT capacity is very high, and supports more than E per floor and sqkm. This implies that every employee could have a DECT phone and still only part of the DECT spectrum is utilised. Remaining capacity may be utilised for data services. The largest DECT installation has about handsets and covers every building and outdoor area within a 1 sqkm area Voice and Data services Typical data services for DECT enterprise applications are Paging, Short message services, Group calls, Automatic alarms, Supervision, Telemetry, Data collection (bar code readers). Several of these services are easily received and handled in a handset. DECT is also very suitable for real time and best effort data medium rate services (0.5-1 Mbps), e.g. laptop PC wireless access to the LAN. The strength for DECT is the unique capability to effectively combine high quality voice telephony with data services in the same base stations. This strength has not yet been fully utilised for medium rate data services by existing products. See Annex 7. - page 20 -

21 3.3 Ad hoc networking and cord replacement applications Wireless LAN 20 Mbit/s aggregated DECT module DECT modu le DECT module DECT modu le DECT modu le DECT module ISDN/PSTN /Cable / DSL /LAN... DECT mod ule DECT GAP DECT GAP DECT mod ule Ad hoc networking is also standardised for DECT. One version, called Distributed Communication, is shown in the figure above. One central unit synchronises and makes the access right checks for all units, but the user data flows directly between the relevant units. The locally aggregated instant traffic could be e.g. 20 Mbps Direct Portable to Portable communications The second version, called Direct Portable Part to Portable Part Communication, provides direct set-up between any pair of handsets or PCMCIA data access cards, belonging to a temporary group of units (<100) with temporary mutually recognised access codes. 3.4 Public pedestrian and WLL applications DECT is also well suited for public pedestrian and WLL applications. Interoperability profile standards are available for both applications Public Pedestrian applications The general availability of subsidised cellular phones combined with low cost low commitment subscription alternatives, limit the business opportunities for DECT public pedestrian systems. - page 21 -

22 It is however possible to have a common infrastructure for pedestrian and WLL applications Wireless Local Loop, WLL, applications The WLL applications support voice telephony, ISDN and packet data internet user data access up to a few hundreds of kbps. Aggregated user data per sector is Mbps, and may be e.g. doubled by introducing optional modulation schemes, e.g. the pi/4 DQPSK modulation. DECT Access Node for WLL LE DAN Fixed Access Units cluster of DECT transceivers and antennas high-gain antennas for range dive rsity for quality and redundancy synchronization DECT provides high capacity WLL services with typically 40 to 150 E average speech traffic per DECT Access Node, DAN, in a 20 MHz allocation. The DAN may be highly sectored and are deployed in cellular pattern. 10 to 22 dbi antennas are used. The figure above shows a typical example of a DECT Access Node, DAN, having a microwave link connection to the local exchange, LE. A DECT WLL system consists of a cluster of several DANs. About 1.5 M DECT WLL subscriber lines are presently in operation, mainly in developing countries. DECT WLL systems are promoted in countries like China, India and Russia. For low traffic density scenarios, the capacity is not an issue, but the range is. High gain directive antennas and WRSs are often applied in order to increase the range of the links. The service and facilities description for DECT WLL requires a range up to several kilometres for a DECT radio link. A Line Of Sight (LOS) range of about 5 km is feasible with 12 dbi antennas at each end and reasonable antenna heights. Thus adding a WRS, could double the range. The - page 22 -

23 figure below, shows how WRS functionality in the subscriber unit provide local intercom functionality without extra hardware. See the section below for information on WRS. Evolution to Cordless in the Home and in small Office LE RNC DAN WRSs WRS with Intercom By adding lamppost WRS, neighbourhood pedestrian service is added to residential cordless users. See figure below. Evolution to Cordless in the Home/Neighbourhood LE DAN RNC Fixed Repeater Units, WRS Coverage Enhancement Unit, WRS - page 23 -

24 3.5 Wireless relay station, WRS A WRS is an additional building block for the DECT fixed network. It has the basic functionality of a normal base station, RFP, but with the advantage of not needing a wired access to the radio exchange or base station controller. Handover is supported as between RFPs. See figure below. DECT Wireless Relay Station WRS For more information see ETR 246 WRS RFP WRS WRS WRS WRS Example with 7 cell WRS cluster with seamless handover WRS is suitable to provide cost effective infrastructures for low traffic density applications, for improving/extending coverage indoors, or outdoors, or behind obstacles and for providing integrated fixed - mobile services from the same infrastructure. WRSs are presently mainly used together with residential and enterprise systems. The WRS use the same radio hardware as a single radio RFP or handset. The WRS works by linking two DECT radio links working on two different time slots. The Instant Dynamic Channel Selection (idcs) functionality is available to each of these links independently. WRS links may be cascaded. - page 24 -

25 4 Positioning of wireless technologies for home (SOHO) applications The main wireless residential products today are cordless phones with the traditional voice service. Wireless data access and wireless PC accessories have a small but increasing market share. Wireless cord replacement for telemetry and control within a home may gain importance in the future. The residential market is very competitive and price sensitive with fragmented best price buys. Unlicensed technologies totally dominate due to required low cost distribution through retailers. Frequency planning and installation by qualified personal cannot be afforded. Different radio technologies will often be found in the same residence. In the US for example a CT0 (or US-CT900) cordless phone and an IEEE b wireless PC access. In Europe you typically use DECT for the voice service, and DECT or b for wireless PC access. The radio technology in the product has little or no importance to the consumer as long as the product works satisfactory. The consumer is normally unaware of which radio technology is used by the product he purchases. Two products operating on the same unprotected spectrum may thus cause unexpected mutual interference. The selection of radio technology is indirectly very important for manufacturer, retailer and consumer. The obvious needs for low cost, telephony quality of the voice service and easy installation leads to requirements on: Range. A single base station must cover the home (including garden). Speech quality. Telephony quality excludes low bit rate codecs and requires some protection of the spectrum. For example, the popular unprotected 2.4 GHz ISM band is not suitable for residential voice services. To this has to be added requirements for the emerging wireless data services: Best effort data services. The main requirement is PC internet access and networking. Range and cost are most important. A protected spectrum is not required. The bandwidth requirements depend on which kind of data access is available to the residence. Required user bit rates depend on application. - page 25 -

26 Voice band data modem access: kbps ISDN access: 128 kbps ADSL access: Generally 2 Mbps down-link, but often limited to 500 kbps. CATV internet access: 5-10 Mbps Satellite internet access: 5 Mbps Real time streaming of voice/music. Some protection of the spectrum is required. Required (down-link) user bit rates depend on application. Radio listening (news): kbps High quality music listening (MP3, MPEG4-AAC): kbps Real time streaming of TV. Protection of the spectrum is required. Required (down-link) user bit rate is about 10 Mbps. One TV channel may require 2-5 Mbps, depending on coding scheme. (2-3 Mbps for MPEG2 4:3, 4-5 Mbps for MPEG2 16:9 HQ, about1 Mbps for MPEG4) The speech service is however still the most important service for residential offerings. Mass market products with suitable mature radio technologies exist. Data services are becoming increasingly important, mainly wireless PC internet access and networking. Residential wireless data access is not yet (2001) a mass market, but seems to be moving into a mass market. The data services are so diversified, that a set of technologies will be required to meet the needs. Suitable products exist so far for best effort user data rates up to 5-7 Mbps (IEEE b WLAN), and for real time streaming up to a few hundred kbps (DECT). As explained below each radio technology has specific properties, which makes it suitable for a specific niche of the wireless residential market. This niche is often related to a main application for that technology. Attempts to extend a technology beyond its main application, will normally result in waste of both money and reputation. Thus different needs will require different technologies. Furthermore, the available technologies and the market conditions differ between Europe and the US. To aim for a relevant residential voice and data market share, it will be required to utilise alternative unlicensed radio access technologies. - page 26 -

27 4.1 Position of wireless technologies for residential access of voice and data services Below is a summary position of main wireless technologies for residential access of voice and data services. A more complete overview of wireless technologies are found in Annex 1. Access ports Europe & other DECT countries The US and Canada Real Time Best Effort Real Time Best Effort Services Services Services Services PSTN/ISDN Telephony DECT No entry CT0, US-CT900 DECT900* No entry Voice band modems DECT DECT b DECT900* (US-CT900) DECT900* b ADSL DECT b DECT DECT900* (5 GHz WLAN) b DECT900* Satellite/CATV/Fibre (5 GHz WLAN) b (5 GHz WLAN) b *) Standard is DECT allowed on the 900 MHz ISM band after May Table 4-1. Main wireless technologies for residential voice and data access The trends for technologies suitable for residential telephony access is very clear. DECT will dominate for telephony access in DECT countries and analogue CT0 in other countries. In the US and Canada CT0 or US-CT900 presently dominate, but we may expect the new DECT900 to take market shares. (New 2.4 GHz ISM band technologies like Bluetooth will not change this domination due to range and quality limitations on this unprotected band heavily used by b best effort services. See sections 4.2 and Annex 3.) Market drivers for data services will be best effort wireless PC internet access and networking b WLAN 2.4 GHz ISM band products are expected to dominate for best effort data services up to 7 Mbps user data. (This excludes other 2.4 GHz ISM band technologies from the main residential access market. See discussion in sections 4.3 and Annex 3.) - page 27 -

28 DECT residential systems will also be essential providers of effective low to medium rate real time streaming and packet data services up to 552 kbps protected user data. These data rates are relevant for voice modem access, ISDN access and ADSL access. ADSL down-link, officially up to 2 Mbps, is in many countries limited to about 500 kbps. Here DECT fits well. DECT is unique in providing protected real time streaming voice/music services. The positioning on the Japanese market will be as in the US, but where CT0 is exchanged with local analogue standards and US-CT900 with PHS. 4.2 Residential telephony voice services Europe In Europe DECT will continue to be the dominant mass market cordless residential technology for several years. DECT has a protected spectrum and unique instant dynamic channel selection processes that provide coexistence of high quality real time (speech) connections in environments of unco-ordinated DECT system installations. The presently dominating DECT speech service will in the future to a larger extent be complemented with cost effective low to medium rate DECT data services. See section A1.1. The market for CT0, CT1 and CT2 is decreasing. See sections A1.3 and A1.4. Bluetooth residential cordless phone applications will probably appear, but are not expected to gain much success due to range and quality limitations in the unprotected and congested 2.4 GHz ISM band. Furthermore, Bluetooth has no cost advantage compared to DECT. See section A The US and Canada Analogue low cost analogue CT0 and digital and analogue 900 MHz ISM band phones, here called US-CT900, will dominate on a fragmented voice service market. Both provide good range properties. CT0 has a protected spectrum. The US-CT900 cordless phones do not have a protected spectrum, but the risk for interference is much lower than in the 2.4 GHz ISM band. Standard DECT is allowed on the 900 MHz ISM band after May It is thus expected that the new DECT900 will take market shares. See sections A1.4 and A page 28 -

29 The DECT derivative PWT has a protected spectrum. But residential applications (nomadic or easily moved products) are not allowed. See section A1.6. We also expect small niche markets Home-RF, Bluetooth, DECT-ISM and other 2.4 GHz ISM band cordless phones Japan DECT is presently not allowed in Japan. The dominating cordless voice technology will continue to be CTs according to older analogue Japanese standard and PHS, which have good quality and range properties. PHS has a protected spectrum and instant dynamic channel selection processes that provide coexistence of real time (speech) connections in environments of unco-ordinated PHS system installations. The PHS technology is less efficient and more expensive than DECT. See section A1.11. The market for analogue CTs is decreasing. Bluetooth and some other 2.4 GHz residential cordless phone applications will probably appear, but are not expected to gain any success due to range and quality limitations in the unprotected and congested 2.4 GHz ISM band Other countries Australia and most countries in Asia (except Japan), Africa and South America have spectrum allocations for DECT. The DECT system penetration in these countries steadily increases. The telephone penetration and wealth in many of these countries is considerably lower than in Europe. Therefore the simpler lower cost CT0 cordless systems, which are allowed in many of these countries, have a higher market share than in Europe. 4.3 Residential data services Europe Market drivers will mainly be best effort wireless PC internet access and networking. - page 29 -

30 802.11b WLAN 2.4 GHz ISM band products are expected to dominate for best effort data services up to 7 Mbps user data. DECT residential systems will also be essential providers of effective low to medium rate real time streaming and packet data services up to 1 Mbps protected user data. These data rates are relevant for voice modem access, ISDN access and ADSL access. ADSL down-link, officially up to 2 Mbps, is in many countries limited to about kbps. Here DECT fits well. See section A1.1. DECT is unique in providing protected real time streaming voice/music services. The DECT user bit rates up to 1 Mbps fit very well for these applications. Both the DECT and the standards have options for higher level modulation schemes, providing for higher user bit rates (about 5 Mbps for DECT and 30 Mbps for ), than those indicated above. Such products are however not yet generally available on the market. See section A1.9. Emerging WLAN technologies for the 5 GHz will be able to provide user data rates up to about 30 Mbps. The relevant 5 GHz bands will be more or less unprotected aimed for best effort services, similar to the 2,4 GHz band. But the lack of ISM devices in those 5 GHz bands and the several 100 MHz of available spectrum, will make it easier to apply interference avoidance mechanisms in the own product, than for the 2.4 GHz ISM band. Therefore, besides best effort services, the 5GHz band is expected to be used also for wireless real time music and video (TV) streaming services. See section A1.10. Residential 5GHz products will for the next years only have a limited niche market. Higher cost and lower range than b best effort service products for will limit the market penetration. Bluetooth residential data applications will appear as cord replacements to accessories for cellular phones and PCs, but are not expected to gain any success for wireless data access to public networks, due to range and bandwidth limitations compared to b. See section A page 30 -

31 4.3.2 The US and Canada and Japan Market drivers will mainly be best effort wireless PC internet access and networking b WLAN 2.4 GHz ISM band products are expected to dominate for best effort data services up to 7 Mbps user data. No technology exists for providing protected real time voice/music streaming services, therefore we could expect to see such connections provided by the 2.4 GHz ISM band products with the inherent risk for quality limitations due to interference form other unco-ordinated connections and microwave ovens. We could also expect real time services from new DECT900 products on the 900 MHz ISM band. But the main application will be best effort data applications. Emerging WLAN technologies for the 5 GHz will be able to provide user data rates up to about 30 Mbps. The relevant 5 GHz bands will be more or less unprotected aimed for best effort services, similar to the 2,4 GHz band. But the lack of ISM devices in those 5 GHz bands and the several 100 MHz of available spectrum, will make it easier to apply interference avoidance mechanisms in the own product, than for the 2.4 GHz ISM band. Therefore, besides best effort services, the 5GHz band is expected to be used also for wireless real time music and video (TV) streaming services. Residential 5GHz products will for the next years only have a limited niche market. Higher cost and lower range than b best effort service products for will limit the market penetration. Bluetooth residential data applications will appear as cord replacements to accessories for PCs and cellular phones, but are not expected to gain any success for external data access due to range and bandwidth limitations compared to WLAN (802.11) technologies Other countries Australia and most countries in Asia (except Japan), Africa and South America have spectrum allocations for DECT. For those countries IEEE b and DECT products will be main providers of data access as in Europe. For countries without DECT spectrum IEEE b will be the sole main provider of residential data access as in the US. - page 31 -

32 5 Positioning of wireless technologies for enterprise (office) applications The positioning of the wireless technologies for enterprise applications has to be understood in relation to the normal wired communication services in an enterprise, which are the PABX with wired extensions for the voice services and the LAN with wired PCs for the data services. The PABX market is a mature competitive market, and basic telephony offerings are very cost sensitive. Software service upgrade packages and additional feature phones can be sold with better margins. The LAN market is also very competitive. Due to the anticipated Y2000 problems, many companies have upgraded modern PABX and LAN installations. 5.1 Wireless indoor services Below are listed essential wireless indoor services within enterprises. Speech: Telephony quality, mobility within the whole enterprise and between buildings, seamless handover, high capacity up to E/sqm (equals one 0.2 E user/20sqm). Low data rate services: Paging, Short message services, Group calls, Automatic alarms, Supervision, Telemetry, Data collection (bar code readers). Several of these services are easily received and handled in a handset. Medium data rate services: WAP, MMS, Video telephony, DPAs, Laptop PCs (low number). Voice Streaming (presently not important). High data rate services: General PC access (laptops mainly). Speech is the most important wireless service within an enterprise. This service is provided by DECT of by public cellular phones. DECT has a local infrastructure and is normally integrated with the PABX services. The cellular phone is normally using the external wide area cellular network, and is typically related to the enterprise local telephony network (e.g. PBX) by a call transfer service. Low rate data services are also very important and have traditionally been served by paging systems, but are now normally part of services supplied by DECT. Medium data rate services have hardly entered the market, except for laptops with WLAN access. High data rate (and - page 32 -

33 medium data rate) services for laptops with WLAN access are being introduced, mainly using the IEEE b technology. The table below visualises how the different services map on the DECT, cellular phones and b technologies b Unprotected spectrum Local radio network Partial/Full coverage DECT Protected spectrum Local radio network Full coverage Cellular phones Protected spectrum External radio network Maybe marginal coverage Voice calls - X X Paging Group calls Supervision Alarms - X - Laptops / PDAs X X x Telemetry Inventory SMS WAP MMS X X - - X X Table 5-1. Different wireless enterprise services mapped on the DECT, cellular phones and b technologies. The following sections will provide more information and further discuss the realism and implications of above mapping. 5.2 Wireless office applications are not mass market drivers It must also be understood, that in spite of the high penetration of public cellular phones and cordless residential phones, today the majority of people in enterprises are by management not perceived to need mobility indoors nor to need to be reached outside the enterprise. Telecom costs are an essential part of the expenses for an enterprise. In Europe in average only % of employees have a cellular subscription paid by the enterprise. Similarly, the lower cost unlicensed local mobility (DECT) is in average provided only for 10-15% of the PABX extensions. It should be noted that wireless access in enterprises has not been and will hardly become a mass market driver. The wired services are in general both of better quality and less - page 33 -