The next generation of telephone users will probably laugh when we explain how we used to stand next to a wall in the kitchen to make a phone call. Mobile communications, already highly advanced compared with a decade ago, will completely change communications in the next few years. Although there are millions of people using mobile phones, most people know little about the mobile telecommunications industry and its technology. There are three types of mobile phone. These are hand portables, pocket-sized hand portables and transportables. The smallest and most popular are the pocket-sized hand portables. These work on rechargeable batteries, which allow an average of up to 80 minutes' conversation. Mobiles that are fitted permanently in a vehicle do not rely on separate batteries. They require an external aerial on the vehicle. This can mean a stronger signal with clearer speech. Transportables have a high power capability and can be used almost anywhere. They come with powerful battery packs for longer, continuous use and may also be put into a vehicle, using its electrics. They tend to be bulkier than hand portables.