FWA - technology and benefit Professor Torleiv Maseng adj. Professor radio communications Department of Electroscience ( Inst. för Elektrovetenskap), Lund University, LTH
FWA: Point to multipoint systems 5-20 km WWW, Internet, broadband services Source: PTS
Telecom in trouble
What went wrong? We are offering a product which few asks for (yet) for a price that nobody is willing to pay
What is the solution? Offer a popular product for lower price, enabled by new technology
Fixed Internet access is such a product Which access technology is the cheapest considering bit-rate, distance etc?
Plain old telephone is such a product In the future basic telephone calls will be carried by Internet
Residential fixed broadband access alternatives Access Technology Assessment Twisted copper pairs, xdsl Short range and low rate Coaxial cable, cable-tv Low rate Fixed radio access, FWA Expensive Fibre to the home Very expensive Power distribution cables EMC problems Broadband satellite access No return link Source: NTNU, Department of Telecommunications
No single access technology will take the whole market The choice of access technology depends on demography and geography 100% wireline Network investment ILLUSTRATIVE 100% wireless Hybrid networks combine the benefits of different access media and technologies Hybrid networks provide the most cost efficient alternative Hybrid network ~30% wireless 0 10 20 30 40 50 60 70 80 90 100 Wireless percentage Source: Nera, PTS
Twisted copper pairs, xdsl ADSL 256 kbit/s - 8 Mbit/s downstream (asymmetric) all the way from central office to subscriber VDSL + fibre to the curb up to 52 Mbit/s on hybrid copper - fibre VDSL + inverse multiplexing up to 52 Mbit/s on copper all the way from central office to subscriber SHDSL symmetric bitrates from 192 kbit/s to 2.304 Mbit/s Source: NTNU, Department of Telecommunications
Coaxial cable, cable TV Total bandwidth =< 4 Gbit/s (=<100 channels, 40 Mbit/s) Tree structure of cable network Shared capacity (different users + upstream - downstream) The cable TV network may provide broadband with broadcast TV in parallel Source: NTNU, Department of Telecommunications
Assumptions Frequency (MHz): 2400 3500 5000 10500 Wavelength (m) 0,125 0,0857143 0,06 0,0285714 Antenna Hight Tx (m): 10 10 10 10 Antenna Hight Rx (m): 2 2 2 2 Transmit power (dbm) 30 28 26 24 Antenna gain Tx (db) 15 15 15 15 Antenna gain Rx (db) 20 23 28 34 Sensitivity (dbm) -100-100 -100-100 Max prop. loss (db): 165 166 169 173 Depth of vegetation (m) 50 Loss due to vegetation (db): 21,6 24,2 26,9 33,6 Maxloss (db): 165 166 169 173
Free space propagation loss margin (incl. some vegetation loss) Considering some vegetation loss, low frequencies are better than high! 2.4 GHz 3.5 GHz 5 GHz 10.5 GHz 50 40 Margin (db) 30 20 10 0-10 0 5000 10000 15000 20000 25000 30000 35000 Distance (m)
The price of a network depends on the range and.. Price 2,4 3,5 5 10,5 28 GHz
and hardware cost Ref: C Brylinski and Thales, from; Elektronik i Norden 23 Aug 2002.
Fixed Wireless Access, FWA 1 Wireless access to fixed terminals Broadband access (up to 100 Mbit/s) Large areas a base station can cover 50-1200 km 2 Rapid deployment Well suited for areas where other broadband deployment is impossible or not economically feasible But, close to line of sight necessary for current solutions Source: NTNU, Department of Telecommunications, PTS
Fixed Wireless Access, FWA 2 Main frequency bands already allocated High frequencies (25-50 GHz) lead to expensive solutions Alternative frequency bands unlicensed bands at 2.5 and 5 GHz licensed bands at 3.5 and 10.5 GHz Rapid development of new technologies smart antennas (adaptive) mesh-technology (relay) mass production of microwave devices Source: NTNU, Department of Telecommunications, PTS
Broadband access in different flavours and environments 10 Gbps 1 Gbps 100 Mbps Fiber 10 Mbps 1 Mbps 0,1 Mbps FWA xdsl, cable-tv Copper access Core networks Cities Residential Rural Sparselypopulated Source: Nera, PTS mm
Broadband access coverage Network example in Norway PtP+FWA 36 Mbps per radio node Approx 5 km distance Speeds of 2 Mbps 3.5 GHz licensed band Several virtual LANs Secured by crypto Very simple to use Cheap compared with all other alternatives Quick to deploy Point to multipoint cell giving subs 2 Mbps wireless internet access Source: Nera
Multipoint to multipoint systems (Mesh) WWW, Internet, broadband services Source: Nera, PTS mm
Conclusions 1 Unlicensed bands Inexpensive equipment, readily available No quality of service, interference Free access to frequencies, congestion Licensed bands < 11 GHz Good solution for rural areas No standard equipment Licensed bands > 11 GHz Attractive capacity, but too expensive equipment Wait for next generation systems (3G=UMTS) Source: Nera, PTS
Conclusions 2 WLAN IEEE802.11b at 2.4 GHz is a success FWA: 3.5 and 10.5 GHz might become a success The success of IEEE802.16 is still to be proven FWA at millimetre/centimetre wavelength will compete/complement with VDSL There will be a mix of systems, the winners will be those which are cheapest! Source: Nera, PTS
Timing is essential! Picture taken at the South African coast during a military exercise by the British Navy. It has been nominated by Geo as "THE photo of the year".