A small start-up says it has technology that will allow mobile operators to deliver large volumes of live TV over their existing 3G wireless spectrum. IPWireless announced the technology, called TDtv, claiming it provides enough capacity over existing 3G spectrum so that mobile carriers won’t have to rely on separate overlay networks to carry live TV programming, which use up relatively large amounts of bandwidth. Though mobile operators around the world have spent billions of dollars over the last few years building new 3G wireless networks in order to deliver new services, experts say their networks are not equipped to handle high volumes of live TV traffic.