Kumu Preps Full Duplex Chip

　　Five years into its life as a startup, Kumu Networks hopes a chip still in an early design phase will drive to volume markets its full-duplex network technology. Full duplex standards are in the works at CableLabs and 3GPP, and a handful of competitors are active in the field.

　　Kumu developed an interference cancelation technology to enable systems to transmit and receive over the same frequency band. It is backed by 20 patents and has been tested by a handful of companies including Cellcom, a cellular carrier in Israel.

　　An RF CMOS chip the startup will make at Globalfoundries aims to pack the technology into a 50mm2 chip consuming about 2W max for use in Wi-Fi access points and LTE base stations. It will support delays of hundreds of nanoseconds to better adapt to wireless reflections. However the chip will not tape out until late this year or early next year, and Kumu is still determining whether it will use a 130 or 45nm SOI process.

　　The chip could deliver as much as 132 dB in noise cancellation, about half of it in the analog domain. That could enable a 5GHz Wi-Fi access point to quadruple the number of channels it supports, said Joel Brand, vice president of product management at Kumu.

　　The company is competing for partnerships with Wi-Fi vendors with GenXComm, a startup that announced in June it is raising as much as $15 million to fund a tape out of a device beyond its current 130 and 90nm proof-of-concept chips. Kumu raised about $55 million to date and is not seeking any more financing.

　　Full duplex technology is making inroads in both wired and wireless nets, Brand said.

　　CableLabs has decided the next generation of its DOCSIS standard will support full duplex at the cable modem termination unit using digital technology believed to include algorithms contributed by Cisco Systems. Separately, the 3GPP is evaluating simulations that showed 70 percent capacity increases for base stations supporting full duplexing. The technology could become part of its Release 16 specification.

　　Cellcom got a 50 percent capacity increase using Kumu’s technology in an 1800 MHz LTE network relaying signals 1,350 meters in a residential neighborhood in Israel. Brand said among a handful of other tests to date, a U.S. carrier conducted trials at 1900 MHz. The trials used a 4x4 inch module, typically in repeaters or relay stations.

　　Among other rivals, Magnacom launched in early 2013 with a novel modulation technology and was later purchased by Broadcom for $50 million. Artemis Networks debuted in early 2014, leveraging interference with distributed antennas to create better cellular links.