A key witness in Apple's patent case against Qualcomm will indeed testify in the trial, after Apple said yesterday that he was no longer intending to appear.

The companies are fighting over three patents that Qualcomm says Apple infringed in the development of some versions of its iPhone. One of those patents allows a smartphone to quickly connect to the internet once the device is booted up. Apple has argued that one of its then-engineers, Arjuna Siva, co-invented the technology and should be named on the patent as well. 

But on Thursday, Apple counsel Juanita Brooks said Siva has retained new counsel that has advised him not to testify. 

On Friday, though, Brooks said Apple had filed subpoenas for Siva and his new counsel Matt Warren. She said Siva had gotten yet another new attorney, who was amenable to his testifying. After the subpoenas were issued, talks become more positive, she said. Siva, who now works at Google, is now expected to testify in court on Monday.

The patent case is just the latest in a wide-ranging legal saga between the two companies. Two years ago, the Federal Trade Commission, aided by heavyweights including Apple and Intel, accused Qualcomm of operating a monopoly in modem chips. The agency argued Qualcomm's high royalty rates stopped competitors from entering the market, which has driven up the cost of phones and hurt consumers. That trial took place in January, and the parties are currently waiting for a decision.

The San Diego trial, presided over by US District Judge Dana Sabraw, is more technical than the other parts of the legal battle. But it could have implications for how your phone is made and how much it costs.

Aside from the boot-up patent, the companies are fighting over two others. One of them deals with graphics processing and battery life. The third lets apps on your phone download data more easily by directing traffic between the apps processor and the modem.