vias shield for nrf51822 system

[Nasib]

Hi! This is the first time that I develop a BLE system with this MCU, I want to know if it is necessary to install so many vias making a shield around the entire pcb. If so, with what parameters (distance between vias, vias holes size and diameter ...)

Thanks a lot.

Best regards.

[haakonsh]

There's no hard requirement for a via-stitch, any will do. 

There is however a requirement for a via fence around any transmission line and antenna, as well as properly placed vias for any RF networks or decoupling capacitors. 

You can study the DK's HW layout for reference.