1 © 2004, Cisco Systems, Inc. All rights reserved. Advances in License Exempt Wireless LANs ITU-R Study Group 8 Seminar, September, 2004 Jan Kruys Cisco Systems International

2 © 2004, Cisco Systems, Inc. All rights reserved. JKR04-Genesis of RLANs Introduction RLANs have become the reference for successful license exempt wireless It is important to understand how this got to be the case Other types of license exempt wireless systems are being proposed and developed How should regulation adapt to these challenges? This material is contributed to interested fora for the purpose of assisting their discussions on the subject of spectrum regulations. The content reflects the personal views of the author; it does not in anyway reflect a Cisco Systems Corporate position nor does it commit Cisco Systems to support the conclusions presented.

3 © 2004, Cisco Systems, Inc. All rights reserved. JKR04-Genesis of RLANs Beginnings In the late 1980s – the FCC opens up ISM bands for license exempt data communications – on the condition that they use spread spectrum technology to avoid interference to each other frequency hopping, Direct sequence, limited maximum power/EIRP to 250mW/1W The computer industry recognizes the opportunity and a flurry of new designs appear – and IEEE is formed to develop a standard The CEPT follows suit soon thereafter – and ETSI develops certification criteria based on a low 100mW EIRP limit

4 © 2004, Cisco Systems, Inc. All rights reserved. JKR04-Genesis of RLANs Slow start The first devices were half the size of todays notebook computers – and almost prohibitively expensive – but engineering got the size down quickly Marketing focused on wire replacement = cost saving – slow overall adoption – but some vertical markets developed quickly – like logistics – few saw the benefit of wireless for the consumer But some saw the spectrum crunch coming and started the work on a 5GHz allocation dedicated to RLANs. – that was 1994

5 © 2004, Cisco Systems, Inc. All rights reserved. JKR04-Genesis of RLANs The transition During the mid 90s the notebook computer comes of age and sales take off 1999: Apple Computer offers wireless for $100 per notebook – for an 11 Mb/s card, integrated into the Apple notebooks – all the PC vendors panic and prepare to offer it too – the wireless industry scramble to meet the exploding demand And sales of wireless cards and APs sales exceed everyones expectations….. – 10 years after the first devices were built

6 © 2004, Cisco Systems, Inc. All rights reserved. JKR04-Genesis of RLANs RLANs today HP iPAQ 5450 PDA HP iPAQ 5450 PDA Sharp M25X Projector Sharp M25X Projector HP Printers Cisco 7920 Phone Cisco 7920 Phone Siemens Medical SIMPad Siemens Medical SIMPad Intermec Barcode Scanner Intermec Barcode Scanner IBM Thinkpad PC

7 © 2004, Cisco Systems, Inc. All rights reserved. JKR04-Genesis of RLANs Rolling on… 2003: sales of notebooks exceed sales of desktops – most of them have wireless integrated the main driver is increased worker productivity An RLAN module now costs less than $15 to build Wi-Fi hotspots have become the hottest new access medium – that is offered by established and new mobile operators WRC-03 allocates 455 MHz in the 5GHz range to the Mobile Service for use by Wireless Access Systems, including RLANs – after tough negotiations with the military about sharing the band IEEE starts development of a high speed version: – > 100 Mb/s, MIMO technology

8 © 2004, Cisco Systems, Inc. All rights reserved. JKR04-Genesis of RLANs Significant others Bluetooth – complete solution for personal area network – assumes to be the only spectrum occupant – only the 1 mW version has made any impact – still implements the circuit paradigm HomeRF – another complete solution – based on last years technology – frequency hopping – still implements the circuit paradigm WiMAX and proprietary outdoor access solutions – optimized PHY/MAC technology for access to IP based services – cover fixed, nomadic and mobile use – notably WiMAX promises to be everything to all

9 © 2004, Cisco Systems, Inc. All rights reserved. JKR04-Genesis of RLANs WiMAX Operation from 0-11 GHz OFDM/QAM TDD/FDD

10 © 2004, Cisco Systems, Inc. All rights reserved. JKR04-Genesis of RLANs Grass roots versus the big bang The take-off of RLANs is due to three factors: – it served the market with the strongest internal standards: computing – it offered a pluggable replacement for fixed ethernet – it was affordable at level of the individual The continued success of RLANs is due to its spectrum sharing design – based on the listen before talk principle Other systems require large scale upfront investment of money and resources – corporate business models are not conducive to bringing new, disruptive technologies to market

11 © 2004, Cisco Systems, Inc. All rights reserved. JKR04-Genesis of RLANs Two factors driving wireless access Wireless is perceived as a major enabler of economic growth – and gets a lot of attention at government level The IP paradigm is spreading to the edge of the network – including the wireless edge – it scales from very small to very large networks – it is very efficient for computer to computer communications – it is reasonably efficient for streaming traffic already a lot of voice backhaul is carried over IP core networks at high efficiency – Wireless has to be(come) IP capable see the success of RLANs 3G is still circuit switched

12 © 2004, Cisco Systems, Inc. All rights reserved. JKR04-Genesis of RLANs The spectral challenge There is never enough spectrum – but the demand for operating range drops facilitates spectrum re-use – and smart technology helps to facilitate co-operation Sharing of spectrum will be the rule – Vertical sharing – with incumbents recognize and leverage specifics through embedded intelligence – see RLANs and DFS: recognition of repetition – Horizontal sharing – among newcomers avoid/prohibit stomping on others share available spectrum gracefully under load

13 © 2004, Cisco Systems, Inc. All rights reserved. JKR04-Genesis of RLANs A complex issue Interference requires overlap in at least one dimension Broadcasting Coding/Information Bandwidth/Frequency Duty Cycle/Time Space/Power RF ID, RADAR WLAN UMTS UWBUWB

14 © 2004, Cisco Systems, Inc. All rights reserved. JKR04-Genesis of RLANs Potential solutions Cognitive Radio Techniques – incumbent interference avoidance/prevention – using different means like detection, geo-location database, pilot signals Footprint reduction – high gain antennas reduce chances of interference into incumbents as well as peers provides significant advantage of spectrum re-use Leveraging IP – IP based protocols are adaptive to load and resource variations accommodates intermittent link errors facilitates spectrum sharing with other users/systems while non-deterministic QoS supports voice and video

15 © 2004, Cisco Systems, Inc. All rights reserved. JKR04-Genesis of RLANs Footprint reduction

16 © 2004, Cisco Systems, Inc. All rights reserved. JKR04-Genesis of RLANs Leverage IP Streaming video over a 5GHz RLAN link – flexibility to accept interference or other interruptions

17 © 2004, Cisco Systems, Inc. All rights reserved. JKR04-Genesis of RLANs A new regulations paradigm? Assume that intelligent sharing is possible – based on detection and/or active avoidance Match characteristics of incumbent with constraints on the newcomers – avoid overlap of sharing dimensions (see UWB) – define interference avoidance criteria statically – e.g. by location data base dynamically – e.g. DFS, beam switching or spread spectrum modulation Determine interference load budget for incumbents and leave it to industry to make best use of that budget Assume that technology and systems behaviour changes with time – consider time limited, success-based renewal of sharing permissions

18 © 2004, Cisco Systems, Inc. All rights reserved. JKR04-Genesis of RLANs Thank you for your attention