 reaches widespread adoption, according to the operators. The number of NFC-compatible phones and take-up among retailers will determine the pace, a spokesman at TDC said. Making Telecoms Work Consumers will be able to use their mobiles to pay for goods, services and travel, at a discount if digital coupons are available, and also open doors at hotels or borrow a book at the library, according to the operators' vision of the future. For users, the operators working together will mean that they can switch from one to the other and still bring their wallet with them, the operators said. For the project to become a success, the operators will need backing from all parts of the technology and merchant ecosystem, including phone makers, banks, card companies and last but not least retailers. The announcement didn't have any details on such partnerships. Operators are increasingly getting together to push mobile payments using NFC. The announce- ment in Denmark follows the creation of similar projects in the U.S. with the Isis network. The operators are hoping to gain greater control of the payments market by offering a single platform, according to market research company CCS Insight. So possibly this marks the start of the big breakthrough, at least in the consumer part of the market. 18.6 Bandwidth Considerations A payment transaction is at most a few kilobytes but some transactions could be significantly more bandwidth intensive. This is not just an access-bandwidth issue but a storage-bandwidth issue. There is not much point in streaming a high-definition television programme to a device with a few kilobytes of buffer bandwidth and/or limited video and audio playback capability. For example, most of us would understand that there is not much point in coupling the VCR and a kettle unless of course it was a very exceptional kettle. There are also possibly at least four types of exchange that need to be supported, best effort, streamed, interactive and conversational: Best effort is for non time critical exchanges, o