When a low quality speech is imposed across the voice the speech quality is increased due to the low noise across the network and the quality of service requirements are imposed due to the GSM quality speech on the network and thus the overall performance of the voice application is increased a lot due to the GSM application. When the load is compared across the three scenarios it is clear that the overall load on the network is more when the IP telephony is considered as the required application and when the GSM is considered the load is reduced a lot and a maximum value is imposed which is very less than the other two scenarios.

Low quality speech application is considered an optimal load on the network is imposed and thus from the overall analysis it is clear that the quality of service requirements is enhanced with the GSM quality speech. When the medium access delay is considered for the three scenarios the load is more with the IP telephony network and this due to the IP protocol implementation and this will reduce the quality of service on the network. 

A minimum load on the network is imposed due to the GSM network and for this implementation the overall quality of service requirements against the voice application and even in this case the low quality speech also imposed the optimal medium access load on the network.

From this overall analysis it is clear that to improve the quality of service across the voice applications GSM level standards are required and this fact is proved in this context. It is observed when the network load is considered more load on the network is imposed due to the IP telephony and this due to the fact the IP protocol is imposing more traffic on the network rather than the CBR traffic that was generated by the GSM and low quality speech.GSM in general generated the CBR traffic where a constant traffic is directed towards the voice destination and thus the overall the network load on the network is reduced a lot.

From this analysis it is clear that if GSM quality speech is used at the application level the impact on the quality of service requirements is directly adopted and it is increased a lot in this context. It can be observed that the overall retransmission attempts made by the GSM quality is very less when compared to the IP telephony and the low quality speech and this indicates that the GSM is best suited to ensure the quality of service requirements and also the case of losing the packets is reduced a lot as the attempts made due to lose of the route is very less.

When the case with the IP telephony is considered the retransmission attempts are very more and a maximum value of 0.65 is recorded and this indicates that the quality of speech is suppressed and also the optimal conditions are violated.

Thus from this overall analysis it is clear the total retransmission attempts are reduced due to the GSM quality aspects and thus the overall performance is improved at the same time against the quality of service requirements.

When the throughput is more the quality of service is reduced a lot and thus in this context the GSM quality voice application is imposing a very less throughput and thus the quality is improved in this context where the maximum throughput is due to the IP telephony as the IP protocol impose more traffic on the network and due to this the overall throughput is increased.

When the case with the low quality speech is considered an optimal throughput is occurred and due to this the overall voice performance is reduced a lot. From the overall analysis of the results it is clear that the quality of service across the voice applications can be improved with the GSM quality voice application. 

Future work

Apart from the work done towards this simulation there is few aspects that need to covered in future and they are as listed below 

  • More number of voice applications can be compared in future to estimate the quality of service requirements
  • More scenarios can be created and more performance evaluation aspects can be compared to understand the importance of quality of service requirements for voice applications