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Showing posts with label Mobile. Show all posts
Showing posts with label Mobile. Show all posts

Tuesday, February 28, 2012

VoIP on Mobile Phones - Playing Around With Networks

VoIP is a prime example of how technology has changed faster than the businesses which provide it. First smartphones made an appearance and caught the carriers flat footed as data usage skyrocketed on their wireless networks. Then VoIP started to make inroads into their revenue streams and caused knee jerk and clumsy attempts to block it like AT&T did with Skype on the iPhone. Telcos then imposed data caps on wireless traffic and also attempted to scuttle the principles of net neutrality.While all this was going on, VoIP has continued to grow and shows no signs of stopping. And it's time for the next technology feature to be incorporated into applications - or perhaps at the OS level itself. Most people these days have multiple pipes to the outside world. They have the regular voice network, their wireless data networks and also the wifi pipe. Depending on the situation and the person using it, they might prefer one network or the other to be used when available. And when more options become available they might want to switch networks in the middle.
A good example is if you're using your wireless 4G network to make VoIP calls while driving. You reach home, still attached to your phone. At this point, you'd like your wifi network to take over. It's more reliable, faster, and free. You should be able to program your phone into detecting home wifi and make the switch seamlessly. And when you move out of your home, your phone should then switch to the 4G network again.
Unfortunately not many applications provide this kind of service - which is sad since it's a natural extension of technology today. More and more people live in wifi worlds where they have access to free wireless Internet connections - specially with the proliferation of work from home capabilities. Such individuals need a way for the phone to switch on and switch off certain networks automatically.
A few applications like Rebtel have begun offering these services. But it's a far cry from the kind of deep operating system level integration we're looking for. VoIP is the ultimate flexible Internet application. You might even call it the pinnacle of Internet technology. And the demand of consumers is going to drive wireless data technology forward like never before. And for that, we are grateful. Because technology changes fast - and we want to make sure that we have the best tools available to us.
Bhagwad is an expert consultant on Secure SIP Providers. He also specializes in Secure Mobile VoIP Systems.

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Tuesday, February 7, 2012

Strategies for Improving Mobile VoIP Quality

Despite the great leaps that VoIP has made over the years, there's a lot to be done in order to make it perfectly easy to use for the average person. It's not necessarily a bad thing right now because the industry is in a state of flux and the current confusion and complexity reflects an atmosphere of experimentation and seeing what works and what doesn't. Different configurations, different SIP providers, varying features pricing models and even business models are all in the mix. Things are slowly settling down though as the industry self organizes. SIP for example has come to be the de facto open standard for all VoIP communications and this is really a huge step.Unfortunately, the lack of standardization can sometimes hurt VoIP quality especially on devices like mobile phones which (to make things worse) also have unstandardized hardware and software. Some platforms like iOS don't allow applications to run in the background and we have to use workarounds such as push notifications instead. For this, and a variety of reasons, mobile VoIP is generally more dodgy than the same application on the desktop. Take any client which has a version for the desktop and a version for the smartphone, and you'll find that the smartphone performs just a little bit worse. There are a few things we can do to address this issue though.

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To a certain extent, VoIP demands a certain amount of CPU power. This has to do with the codecs in use by VoIP and the encoding/decoding times can increase the apparent lag on the device. VoIP codecs are also designed for maximum compression to preserve bandwidth. So naturally, even a little bit of packet loss can result in significant degradation of VoIP quality. There are many different codecs and they all vary as to their compression capability and bandwidth requirements. The best ones like G.729 perform well on both counts. Unfortunately, it's also a licensed codec and therefore isn't free.
In the future, perhaps some of the VoIP processing can be passed along to a dedicated hardware chip instead of doing it programmatically. This is far more efficient and should represent some major speed increases. Other speed increases can come from using wifi on a router that has VoIP based QoS rules embedded into it. This will be more reliable than the wireless 3G or 4G network and will improve VoIP quality significantly.
Bhagwad is an expert consultant on Making an SIP Account. He also specializes in Mobile VoIP Phones.

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