The back and forth between Dish Network and Sprint continued today, as Dish submitted an ex parte filing that blasts Sprint's suggestion that the FCC do more to protect the H Block from being interfered with by Dish's AWS-4 spectrum. 

Dish has already conceded a terrestrial guard band at 2000-2005 MHz, OOBE limit of -30 dBm/MHz at 2000 MHz for AWS-4 mobiles, and OOBE limit of -49 dBm/MHz at 2005 MHz for H Block base stations, which Dish says offers the only solution that achieves the Commission’s twin goals of expediting an auction and increasing the value of the H Block for broadband use. 

In its filing, Dish called Sprint’s continued opposition to proposal "merely another transparent block a new entrant from competing in the marketplace." 

Sprint has panned Dish's proposal, saying in a filing on Friday that it would "substantially reduce both the prospective value and wireless broadband utility of the H Block." 

"Rather than offering an improved spectrum management solution that permits both AWS-4 and H Block to be deployed for broadband services, Dish’s “new proposal” is remarkably consistent with its previous positions in this proceeding, in which it first argued for relegating the H Block to a guard band for DISH’s prospective AWS-4 operations and then, upon gaining no support for that result, proposed limiting the H Block to “small cell use," Sprint argued. 

Sprint called Dish's offer to voluntarily designate the lowest 5 MHz of its AWS-4 uplink at 2000-2005 MHz as an internal terrestrial guard band "vague and ambiguous, and of dubious value when compared to the Commission’s draft proposal."  

"Dish fails to explain what this “voluntary designation” would entail, how long it would last, how it would be enforced, and how and whether it would bind successor AWS-4 licensees," Sprint argued. 

Sprint also included a diagram of a Washington Nationals stadium in its filing that suggested a large amount of interference from a Dish device on the H Block. 

Dish called the image a "rough, unscientific illustration" which depicted "incorrectly calculated radii" and offered "no technical justification" to refute industry analyses that demonstrated the sufficiency of an OOBE limit of -30 dBm/MHz or higher for broadband devices.

"Moreover, AWS-4 devices will operate at much lower transmit power levels, and the H Block devices will operate with a significant amount of margin," Dish argued. 

Dish also refuted Sprint's claims that Dish’s proposed OOBE limit of -49 dBm/MHz at 2005 MHz for H Block base stations would increase network costs by hundreds of millions of dollars.

"In fact, LTE base stations currently operate at levels close to this limit, and any additional modifications, to the extent required, will impose no significant cost increase," DISH claimed, adding that it has requested that vendors perform an analysis on base station OOBE performance. 

The flurry of comments from the two companies comes just ahead of a Wednesday deadline, when the FCC is set to vote on the rules governing the terrestrial use of Dish's AWS-4 spectrum, as well as the rules for the H Block auction.