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Samsung has added Apple's latest handset to a US patent lawsuit claiming the iPhone 5 infringes eight of its technologies.

The disputed innovations include a way to , and a method to .

Samsung had already filed claims against earlier iPhones and iPads.

It coincides with calls from a judge for "major reforms" to US patent law.

Judge Richard Posner, who previously oversaw a legal dispute involving Apple and Google's Motorola unit, said that protection available to software patents was "excessive".

Samsung's legal move is the latest in a long running battle with Apple.

The US firm has claimed that the Galaxy device maker copied the look and iOS system software found on its tablets and handsets.

Although several of Apple's claims have been rejected, it recently scored a major victory when a California-based jury ruled Samsung should pay it over $1bn (£620m) in damages.

Samsung has had its own courtroom successes, including a ruling in August that Apple had infringed two of its wireless communication patents in South Korea. It resulted in an order for the iPhone maker to pay 40m won ($35,000; £22,000) in damages.

The US lawsuit involving the iPhone 5 dates back to April when a complaint about other devices was filed in the Northern District of California. The case is due to go to trial in March 2014.

It involves two so-called Frand patents - technologies Samsung has an obligation to licence on "fair, reasonable and non-discriminatory" terms because they are recognised as being essential to data transmission standards. In other words, if Apple agrees to pay what is deemed to be a fair rate then Samsung will be obliged to let it use the technologies.

The other six disputed innovations are feature patents, and in theory Samsung could force Apple's products off the shelves if it does not remove the functions from the devices.

Patent consultant Florian Mueller on his blog earlier this year, noting that Samsung owned about 30,000 US patents in total. Several of these include 4G LTE technologies which the Seoul-based company has hinted could be the basis of further lawsuits.

HTC, Motorola, Microsoft, RIM and other tech firms are also involved in ongoing US lawsuits.

Legal experts have expressed concern at some of the tactics being used, including Judge Richard Posner who threw out a case involving Motorola and Apple in June, rebuking both firms.

He has now followed this up with a blog post in which he calls for an .

"Nowadays most software innovation is incremental, created by teams of software engineers at modest cost, and also ephemeral - most software innovations are quickly superseded," he wrote.

"Software innovation tends to be piecemeal - not entire devices, but components, so that a software device (a cellphone, a tablet, a laptop, etc) may have tens of thousands of separate components (bits of software code or bits of hardware), each one arguably patentable.

"The result is huge patent thickets, creating rich opportunities for trying to hamstring competitors by suing for infringement - and also for infringing, and then challenging the validity of the patent when the patentee sues you."

The judge said that 20-year-long patent protection made sense for pharmaceutical drugs which require development costs running to hundreds of millions of dollars, need extensive testing and subsequently remain on the market for decades.

He said such factors did not apply to software, adding that a firm that invented a new technology would benefit from being the first to use it and would also gain a reputation for innovation.

"My general sense... bolstered by an extensive academic literature, is that patent protection is on the whole excessive and that major reforms are necessary," he wrote.

The tech news site Ars Technica, , noted that Judge Posner did not have the power to shape US patent policy, but added that his views were likely to be discussed by policymakers.