| VoIP has revolutionized the way telecommunication is | | | | of data packets. |
| done. Voice over Internet protocol allows voice | | | | It is important to maintain very low bit error rates to |
| packets to be sent over Internet bandwidth enabling | | | | offer high quality voice services to customers. Jitters |
| cheap communication. There are many companies | | | | are another technology hurdle that is faced by |
| which offer voice over Internet services and some | | | | satellite VoIP service providers. It is used to calculate |
| of the leading ones are Vonage, Skype, Yahoo and | | | | the delays in packet arrivals that happen because of |
| Net2Phone. Consumers can access VoIP over | | | | network delay. If this factor is not within acceptable |
| Internet connections like broadband and DSL. Satellite | | | | limits the quality of voice becomes poor and the |
| Internet is a new technology that has become very | | | | receiver may not be able to enjoy a good |
| popular in recent times and VoIP providers are able | | | | conversation. Jitter buffers are used to overcome |
| to offer services to customers in remote regions | | | | this hurdle and ensure that there is less delay in the |
| using it. It will still take some time until VOIP by | | | | network. Researchers and scientists are working |
| satellite is ultimately stabilized and customers can | | | | relentlessly to overcome all hurdles that come in way |
| enjoy the full benefits. | | | | of experiencing a smooth voice call through satellite |
| Some of the challenges faced by service providers | | | | Internet. |
| include packet loss, jitters and limited bandwidth. | | | | VoIP by satellite is not ideal because of some more |
| Service providers like Hughes and Skyframes which | | | | factors. Latency factor refers to the time delay in |
| have their own satellites are teaming up with the | | | | locating the Geo-stationary satellite and the speed of |
| VoIP providers to offer voice services to customers. | | | | light. There is a delay of 280 msec because of |
| Designing a VoIP network would require details on | | | | latency factor. Traffic congestion in the network also |
| the bandwidth requirement for VoIP data. Satellite | | | | affects the quality of VoIP service. This can result in |
| Internet providers are facing challenges on the | | | | voice packets being dropped, delayed or reaching the |
| bandwidth capacity that would be required to offer | | | | receiver out of sequence. Compression technology is |
| VoIP services via satellite channels. G.729 (b) | | | | another parameter for delivering high quality VoIP |
| encoding with a 40 b payload and header | | | | service. There are two compression technologies that |
| compression would require 10 Kbps of bandwidth. | | | | are followed as industry standards. The G.729 codec |
| Packet loss is another challenge faced by service | | | | uses bandwidth of 18Kbps and RTP uses around 10 |
| providers offering satellite VoIP services. Packet loss | | | | Kbps per second. If service providers are able to |
| causes degradation in voice quality. The protocol used | | | | cope with the technological challenges of VoIP over |
| for voice traffic transmission is UDP/IP and if the | | | | satellite, it will not be long before remote areas of |
| data packets are corrupted they cannot be | | | | the United States can connect with the rest of the |
| retransmitted. TCP/IP protocol allows retransmission | | | | world. |