Another new feature is the HLR Cache for our SMS Center. The HLR cache stores information about the location and state of the target mobile phones for outbound campaigns and MT SMS.
In the SS7 network MSU (Message Signal Unit) are used for getting for routing information, sending SMS and for getting delivery reports about the result of the transmission.
SMS aggregators and others with direct access to the SS7 mobile network are billed by number of MSUs . These companies can save money by enabling the HLR Cache. The HLR Cashe is totally transparent for SMSC users.