Broadcom is about to bring a new meaning to dual-band Wi-Fi. The chip maker announced today at Mobile World Congress the first 802.11ac (or 5G Wi-Fi) combo chip, the BCM4359, that sports real simultaneous dual band (RSDB) for mobile devices.
Traditionally, existing dual-band Wi-Fi clients, such as the iPhone 6, when connecting to a dual-band router, such as the Asus RT-AC68U, can only work on one band, either the 2.4GHz band or the 5GHz band, at a time. In other words, despite having dual-band hardware, up till now you could only make a single-band connection between two devices.
The BCM4359 chip, however, enables clients and routers to transmit and receive data over the two 5GHz and 2.4GHz bands simultaneously, potentially improving the speed as well as the quality of the connection a great deal. Essentially this is basically like having two separate Wi-Fi connections combined into a single connection. Broadcom says the BCM4359 chip supports the dual-stream (2×2) setup of 802.11ac that has a top speed of 867Mbps. It can quickly switch between the traditional single-band mode to RSDB mode for applications that require concurrent multiband connections for higher quality of service.