3, 18, 23, 26, 28, 32 and 38 GHz with a range of dish antennas from 0.2 to 3.7 M. The products use 4 to 256 QAM adaptive modulation and scale from 3.5 to 56 MHz channels. RF output power scales from +30 dBm (CQPSK at 6 GHz) to +16 dBm (256 QAM at 38 GHz), the receiver sensitivity thresholds for a one in 106 bit error rate scale from -59 dBm (256 QAM in a 56 MHz channel at 38 GHz) to -91 dBm for C QPSK at 6 GHz and the throughput scales from 4.1 Mbps to 345 Mbps. NSN having a matching portfolio though scaling to 450 Mb/s per carrier. These systems are usually frequency division duplexed. Other option include 5-GHz systems using the unlicensed 5-GHz spectrum (802.11a) and/or the 60-GHz unlicensed band and/or the 'lightly licensed' 80-GHz band. These systems are usually time division duplexed. As frequency increases bandwidth increases and antennas get smaller for a given gain. A one degree beam width antenna for example gives about 50 dBi of gain. Conversely at a given frequency, the bigger the dish the higher the gain. This translates into higher throughput but mast costs will increase, a function of weight and wind loading. The problem (and opportunity) with microwave links is that as you move into the millimetre bands (30 to 300 GHz) the wavelength is the same length as a raindrop. 1 This causes non- resonant absorption that has to be accommodated in the link budget and/or by rerouting in exceptional but localised weather events (thunderstorms). There are also nonresonant absorp- tion peaks for water at 22 and 183 GHz and oxygen at 60 and 119 GHz. The oxygen peak 60 GHz is what allows this band to be made available as unlicensed spectrum as the absorption, of the order if 15 dB per kilometre provides protection against system-to-system interference. See 3G Handset and Network Design, Chapter 15, page 368. Wireless Core Network Hardware Note that these are line-of-sight systems. With fibre, cable or copper you can turn a corner but with microwave you can only do that by installing another microwave dish and/or re