The best two way radios for Indoor Users are UHF, MotoTalk, or PoC Devices. These two way radios all use frequencies that do well penetrating concrete and other obstructions. Here are some differences between the types of walkie talkies available.
UHF Two Way Radios are the most common two way radios found in use today. Most businesses using walke talkies today are using UHF. UHF two way radios come in 1, 2, 4, & 5 Watt Models and with as few as 1 channel and as many as 256. There are analog and digtial UHF two way radios with some being capable of doing both. If you've never used two way radios, buy digital because they're clearer, offer better battery life, and better range. UHF two way radios are typically compatible between Manufacturers. UHF two way radios require an FCC License.
MotoTalk is a Digital platform created by Motorola. These digital walkie talkies are small, easy to use, and do not require any FCC License. Twowayradios using MotoTalk work in buildings up to 300,000 square feet and about 25 floors. MotoTalk Digital Two Way Radios are 1 Watt. These are proprietary technology and are not compatible with other brands of two way radios.
PoC Devices are a new category of two way radio. PoC stands for Push to Talk Over Cellular but these radios also work over WiFi Networks so we include both WiFi based two way radios and PoC two way radios. These units require WiFi or a Cellular Connection to communicate and do not use traditional two way radio frequencies. The advantages are better audio and the ability to communicate over larger areas without buying additional expensive equipment.