International Journal of Computer Applications (0975 – 888) Volume 48– No.9, June 2012 33 The Effects of Ostentatious Calls in Gsm Networks Osahenvemwen O.A., Department Of Electrical And Electronics Faculty Of Engineering And Technology. Ambrose Alli, University. Ekpoma, Edo State, Nigeria. Edeko F.O. Department Of Electrical And Electronics Faculty Of Engineering And Technology. University Of Benin. Benin, Edo State, Nigeria Emagbetere J. Department of Elect/Elect Engineering Faculty of Engineering and Technology. University of Benin Benin City, Edo State. ABSTRACT In this paper, we investigate the possible effect of ostentatious (flash) calls in mobile communication networks (GSM) in Nigeria. The GSM network consists of physical and logical channels used to convey digit information signal from one network element to another. The Globacom network in Nigeria was investigated in a period of one year duration. An average traffic data (A-interface MSC) were collected from the OMC-network element. Also, it was observed from the result analysis that complete calls which is a major factor in revenue generation consist of both answer calls with 42 percentage and unanswered calls with 58 percentages. These unanswered calls are made up of both redial calls and ostentatious (flash) calls which are transmitted through the limited transmission channels without financial benefit accrue to the mobile communication operators. It were deduced from investigation that the traffic in erlang for average number of unanswered calls in 1 hour is 4151.92 erlang and one (1) call is 0.0023 erlang. In this paper, we highlighted the possible effects of unanswered calls, solutions of reducing the high number of unanswered calls and reduction in unanswered calls will leads to remarkable low number of block calls experience in the Mobile Communication network (GSM). Keywords Ostentatious (flash) calls, Redial calls, unanswered calls, channels and revenue. 1. INTRODUTION As the demand for wide variety of service such as emails, stock quotes, surf the internet and electronic commerce over the air or M-commerce are needed from mobile operators. In order, to achieve a good desired Quality of Service (QOS) the issue of transmission channels must be handle with great important. The transmission channels are limited in resources and it‟s expensive. This transmission channels are used to convey digit information signal in bit from one network element to another [8],[9]. The 13kbps bit rate is transfer from the Mobile Station (MS) through (traffic full rate channels in) the air-interface to the Mobile Switching Centre (MSC) through the A-interface at 64kbps.The Transcoder (TC) is responsible for the conversion from 16kbps to 64kbps and vice versa. The 16kbps bit rate resulted from 13kbps full rate traffic channels, with additional 3kbps used between the transcoder and the BTS for carrying the 260-bit vocoder block (equivalent with 20ms of speech) and for inband signaling (information about the speech coding algorithm, type of call etc)[7] shown in Fig 1. Fig. 1: The GSM interface system The air-interface or um–interface uses two types of channels; these are the physical channel (timeslot) and logical channels [6]. The physical channels are generate from a set of bandwidth (example GSM 900) partition into 124 carrier frequencies, each carrier frequency is subdivided into 8 timeslots or physical channels uses Time Division Multiple Access (TDMA) techniques. These timeslots are used to convey logical channels such as traffic channels (full rate traffic channel 13kbps and half rate traffic channel 5.6kbps) and Control Channels (CCHs) which is divided into three channels such are Broadcast Control Channels (BCCHs), Common Control Channels (CCCHs) and Dedicated Control Channels (DCCH) [2],[1]. The MS make used of BCCHs during initialization, it consist of three channels. Thereafter, the MS is ready to make or received calls using four (4) other different logical channels with a signaling rate of 64kbps shown Fig 2. Abis-interface is the interface between BTS and the BSC .It uses a PCM 30 interface with a transmission rate of 2.048Mbps, which is partitioned into 32 channels of 64kbps each [4],[3].