There are multiple levels of cellular certification. No device will be allowed on the cellular networks in large volumes of units until it has passed the End Device certification. The first level of certification is for the cellular chipsets from the manufacturers. Chipsets that pass these certifications can be designed into devices that advance to the next level of certifications. Devices like cell phones take these chipsets and proceed to end-device certification. For products that will not be driving millions of units, the costs associated with this certification are too high to justify, so those lower volume devices often use modules. Module manufacturers take the certified chipsets and add more functionality and supporting circuitry, enabling devices that will be driving tens of thousands to hundreds of thousands of units. The module certification requires passing a long list of tests on the power supplies, transmit and receive circuits, as well as the SIM card circuit and antennas. Like the Chip level certification, the Module level certification still requires another level of certification to get to an end product. Every device needs to pass end-device certification. The more certifications that have been passed in the technology that is in the device, the faster and less expensive it is to pass this level of certification. Using a certified module is strongly recommended by all of the carriers and test houses. In fact, many recommend going an extra step and using a certified modem that has already passed the end-device certification if the user’s unit volume does not justify the time to market delay and cost of certification.