The trend in mobile telecommunications across the globe has been towards devices that are the mobile window into a person’s digital universe. In 2013 smartphones outsold feature phones globally for the first time on a unit basis. Several companies have focused efforts on creating inexpensive smartphones for the emerging markets, where, in many cases, these devices may be the only link those consumers have to the internet and the rest of the world. This expansion has resulted in devices that have many more communications bands and codecs than we have had in the past. It is not uncommon to find single devices that will communicate via UMTS, GSM, CDMA, LTE (VoLTE), and WiFi (VoIP). Some of these modes of communication have to support multiple voice codecs for each mode depending on the network or service provider. In all cases the switching between modes and performance of the system must be seamless, as past performance is no longer acceptable to the consumer. After 2013, mobile communication using VoIP and video conferencing apps has increased in accelerating pace.
From a voice quality standpoint, the AMR Wide Band codec is in widespread use globally, and the 3GPP EVS (Enhanced Voice Services) codec was finalized in 2014 and the first commercial deployment took place in South Korea in 2015. Demands for IP based communication also in poor networks have caused a rising interest in low bitrate voice codecs. The audio recording capabilities of the devices have improved to offer high bit rate and 24 bit capture in some cases. There are also many products out on the market that allow multichannel audio recording via internal microphone arrays to compliment the video recording on the devices. Use of stereo or spatial audio also for communication applications was increasingly studied in scientific research during the first decade of 2000. The first commercial applications have emerged, and we can see this as one trend that may change the way we communicate, together with the rise of technology and applications for augmented or virtual reality.
Voice controlled user interface in the mobile devices has evolved to Virtual Personal Assistants that extend to other platforms as well. Interaction with Natural Language is also coming to chatbots that are used for automating business processes like ordering a pizza over a phone call. Communication with these virtual assistants sets different requirements to smart phones and VoIP systems than what was common with human to human calls and new technologies are being developed to raise the quality of these features. We can estimate that in near future using a mobile device for voice communication between a user and a digital assistant or a bot will be as typical as communication between humans. This communication will happen both through the same signal paths as normal voice communication and through dedicated paths, using signal processing and coding optimized for voice recognition engines.
Advancements in usability in all environments have come in the form of noise adaptive technology in voice call, content playback and voice control. Voice communication and voice recognition have benefitted from algorithms that adapt uplink noise reduction or algorithm parameters based on noise type and level. This becomes even more important when voice control and new types of endpoint devices emerge. Smart speakers or communication hubs for homes, conferencing phones for office environment are used from further away compared to personal mobile devices, so signal to noise ratio may be poor to start with. Likewise downlink audio and content playback have benefitted from noise adaptive algorithms. Another new feature that assists the usability in various environments has been the use of smart amplifier technology. The technology constantly monitors the content and the speaker to produce optimal loudness or bandwidth, while maintaining safe drive levels for the speaker. This technology paired with new high voltage amplifiers work together to produce impressive audio quality in many environments.
On the content side of the business, the trend has been from localized content to cloud based content. This has allowed the consumer to consume the same content across all devices, which has posed challenges in the small power conscious mobile devices.
The move from portable phones with a few extra features to the mobile hub of the consumer’s digital world, are reflected in the standards world where the scope of standards as well as their names have had to change to keep up.