, typically GSM and WCDMA. Any discussion of the economics of adding an additional frequency band to a handset therefore has to comprehend the technology or technologies used to access that band. The technology used (GSM and/or GSM/UMTS in 1997 or GSM and UMTS/LTE in 2012) in- fluences the RF architecture of the phone, the RF component cost of the phone and the nonrecurring engineering cost of getting that phone to market. It was of course possible to produce UMTS only devices and such devices were developed and sold into some markets, for example Japan. Similarly today, there are iPhone products for the US market that are dualband and some LTE-only dongles. There is little point in adding additional bands if additional cost is incurred. 2 http://www.rttonline.com/documents/rfcosteconhsetss.pdf. Telecommunications Economies of Scale Table 4.6 Assumed future spectrum allocations by technology in 2007 Handsets supporting Single-mode Dual-Mode Refarming Frequent Rural other GSM/UMTS Handsets Traveller Heavy User coverage technologies Quadband Quadband and Handsets Handsets Handsets Handsets For example, 850/900/ UMTS/LTE 2.6 or 3.5 1800/1900 1900/2100 UMTS/LTE UMTS at UMTS/LTE UMTS at GHz Wi 900/1800 850/1900 at 2.6 GHz 470-862 Quadband Quinband dual Quinband Quinband Sextuplet Septuplet Octo- or dual mode dual mode band dual nonoband Additionally, each extra band incurs additional insertion loss and loss of band-to-band isolation. The same applies to multiple technologies. On the other hand, a dualband or single- band single-technology phone can only be shipped to a small local market and will have limited global roaming capability though this only matters to people that regularly travel (less than 10% of the global population). The 2007 study assumed seven handset categories each supported by a specific band plan. This is shown in Table 4.6. This excluded the probable need to support Band IV in the US (the AWS band at 1700/2100 MHz where T Mobile was the dominant spectral investor) and possible need to support Ban