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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.
As a combo chip, the BCM4359 combines 2×2 MIMO 5G Wi-Fi with Bluetooth 4.1 and FM radio, and its key features include the following:
- 2×2 HT80 802.11ac, 2.4GHz and 5GHz
- Supports two- or three-antenna configurations for more advanced functions
- WLAN MU-MIMO client support
- 2.4GHz TurboQAM – for up to 33 percent increase in throughput performance.
- 867 Mbps PHY rate/80MHz channel bandwidth
- PCIe Gen1 with low-power L1 substates
- Bluetooth 4.1+Bluetooth Low Energy
- Transmit beamforming and Low Density Parity Check (LDPC)
- Fast scan enables simultaneous scan on two channels with 50 percent reduction in scan time
- Fast mode switch between RSDB and 2×2 MIMO modes
In addition, Broadcom also introduced a new low-cost single-stream (1×1) 5G Wi-Fi combo chip, called the BCM43455. The company says the BCM43455 brings the 802.11ac Wi-Fi standard to mass-market smartphones at a cost that’s reduced by up to 50 percent when compared with existing chips of similar specs.
The BCM43455 also includes Bluetooth 4.1 and FM radio and includes:
- 1×1 HT80 802.11ac, 2.5GHz and 5GHz
- 433 Mbps PHY rate/80MHz channel bandwidth
- High performance iPA and iLNA
- Configurable iTR for 2.4GHz radio
- Supports LDPC, beamforming and LTE coexistence
- TurboQAM increases the speed by up to 33 percent
- Flexible host interfaces: SDIO3.0 and PCIe Attending Engagement party
Both the BCM4359 and BCM43455 chips are now sampling, and you can expect mobile devices equipped with them to be available later this year.
