From a post to Baen's Bar Honorverse dated April 14, 2004:

Grav pulse comm post Ashes of Victory

    Another point that someone asked about (and you know who you are) is the bandwidth of the latest generations of Manticoran FTL communicators. The last time that I posted about this was around the time that Echoes of Honor was released, I think. That was in 1913 PD. War of Honor began in 1918 PD, five years later, and ended in 1920 PD, which means that an additional seven years of R&D time has elapsed as of the beginning of The Shadow of Saganami. Even under the Janecek Admiralty, this was an area which continued to receive heavy funding and support, and additional advances have been made. The ability to manipulate and "modulate" frequencies in a warship's nodes has increased very, very significantly. Even more importantly, however, the RMN has very recently (like roughly concurrent with the end of War of Honor) began deploying a completely new form of FTL communicator. Rather than using the nodes of the transmitting unit, it is effectively an entire cluster of directional grav-pulse generators which is small enough to mount in a recon drone. It is shorter ranged than the all-up system which still uses the impeller nodes of a starship, but it has an effective range (largely dependent upon the sensitivity of the receiving unit) measured in double-digit light-minutes. By pulling out all the stops in the use of the new modulation techniques, increasing the number of transmitting sources by adding additional nodes to the new communicator's "cluster," and greatly improving the signal enhancing and processing capabilities of the receivers aboard its ships, the RMN is now able to real-time quite accurate and comprehensive sensor information from its drones to the ships which deployed them. The system is still being improved, and remains considerably short of the eventual capabilities predicted by Sonja Hemphill, but it is significantly more capable of transmitting relatively dense data streams than earlier systems were.