Some recent patent’s filed by Apple may suggest that they are looking to incorporate the ability for their MacBooks to connect to LTE, 3G, or 4G networks without the needs for additional modems.
Currently if you want to connect to any of these networks and external modem is required. But this may look to change in a future MacBook release according to the patent.
One patent file discovered by patentlyapple.com reveals that Apple has filed for a telephonic MacBook with a magnetically coupled antenna.
The patent states that the wireless communication circuitry in the MacBook may be used to handle cellular telephone communications in one or more frequency bands and data communications in one or more communication bands