DataTAC is a narrowband wireless network that began as a joint venture between Motorola and IBM for use with two-way pagers and personal digital assistants (PDAs). The network is currently used by some BlackBerry and eLink handheld communications devices. DataTAC networks are operated by Motient Corporation in the United States and Bell Mobility in Canada.
DataTAC devices operate in the 800-MHz radio frequency (RF) band at data speeds of up to 19.2 Kbps. Messages are sent and received in the form of 512-byte packets that can be combined into blocks called Service Data Units, each of which can contain up to 2,048 bytes. Because of its relatively low frequency and consequent long wavelength, DataTAC facilitates extensive coverage with in-building penetration. DataTAC devices offer advanced messaging services as well as seamless roaming.