Limitations of Mobile VoIP

The three fundamental issues with Voice over IP (VoIP) on wireless data networks (also known as packet-based networks) are:

  • Latency – the amount of time/delay taken between when a data packet is sent to when it is received
  • Jitter – this is a variation in the delay on the network; in other words, latency is not a fixed time; it varies depending on network conditions
  • Packet Loss – due to network congestion and noise/interference

The packet delivery scheduling algorithms for packet based wireless networks such as Wi-Fi, 3G and LTE were designed primarily for non real-time applications and typically have a one-way Latency in excess of 200 milliseconds; these latencies lead to a poor user experience for any real-time data activity such as voice over IP or video-streaming.

Jitter on wireless packet networks impairs sound quality as missing data packets fail to synchronize between speaking and playback. A long-delayed packet means that the call will have an unacceptable delay between the talking parties. Sometimes those sound packets get ignored by the device, resulting in some missing speech during a call.

Compounding delays and packet drops, wireless networks can be congested or can experience radio signal interference. Congestion and noise cause packets to be corrupted and the majority of corrupt packets cannot be retransmitted and are simply lost “in the air,” resulting again in some missing speech from Packet Loss.

At Horizon Globex, we have a very detailed knowledge of these wireless data network issues and have invented a totally new solution to overcome latency and jitter in a way that achieves a much higher likelihood of a packet arriving in time and not being dropped. Our awareness of these problems led us to develop a completely new algorithm for sending and receiving (and ordering) voice packets so as to reduce the likelihood of packet loss due to congestion.

Only by approaching VoIP on wireless networks in a completely new way were we able to overcome these issues – the traditional methods of sending, receiving and ordering VoIP were conceived and developed for wired (Ethernet) packet networks. Horizon Globex is designed to be different – very, very different.