InnoWave Telecommunications

Applications Information TelecommunicationCircuits

Thu, 23 Feb 2012 06:43:32 GMT

Double sideband suppressed carrier modulation is the basic application of the MC1496. The suggested circuit for this application is shown on the front page of this data sheet. In some applications, it may be necessary to operate the MC1496 with a single dc supply voltage instead of dual supplies. Figure 26 shows a balanced modulator designed for operation with a single 12 Vdc supply. Performance of this circuit is similar to that of the dual supply modulator. The circuit shown in Figure 27 may...

Ad Hoc Wireless Networks WirelessNetworks

Tue, 21 Feb 2012 08:25:40 GMT

An ad hoc wireless network is an impromptu network formed by several wireless devices, such as PDAs, laptops, and phones, without relying on an existing network infrastructure Perkins, 2000 . These devices denoted as nodes may be mobile and use a common wireless technology such as WiFi. To facilitate communication among the nodes that are not directly in the radio range of one another, the other nodes act as intermediate routers, just like routers in the Internet. Such networks are useful in...

Info Frx MeshNetworks

Thu, 16 Feb 2012 13:23:00 GMT

52. E. Setton, X. Zhu, and B. Girod, ''Congestion-optimized multi-path streaming of video over ad hoc wireless networks,'' in Proceedings of the IEEE International Conference on Multimedia and Expo, vol. 3, Taipei, Taiwan, pp. 1619-1622, June 2004. 53. K. Madepalli, P. Gopalakrishnan, D. Famolari, and T. Kodama, ''Voice capacity of IEEE 802.11b, 802.11a and 802.11g wireless LANs,'' in Proceedings of the IEEE Global Telecommunications Conference GLOBECOM , vol. 3, pp. 1549-1553, December 2004....

Info Sjp SwitchingSystems

Tue, 14 Feb 2012 16:12:16 GMT

For the present day networks which support voice, data and many other services, erlang is better measure to represent traffic intensity. Cent call seconds CCS . It is also referred as hundred call seconds. CCS as a measure of traffic intensity is valid only in telephone circuits. CCS represents a call time product. This is used as a measure of the amount of traffic expressed in units of 100 seconds. Sometimes call seconds CS and call minutes CM are also used as a measure of traffic intensity....

Info Llt CircuitDesign

Tue, 14 Feb 2012 00:29:17 GMT

0 2 4 6 8 10 12 14 Drain-to-source voltage v vj Figure P3.2. 0 2 4 6 8 10 12 14 Drain-to-source voltage v vj Figure P3.2. 3.9 An AM signal applied to an envelope detector has carrier frequency oc 250krad s. The upper envelope is a triangular waveform which goes from 10V to 2V and back up to 10 V at a constant rate in 0.2 ms the lower envelope is similar . Assuming that the diode is ideal, calculate the maximum time-constant of the detector load to avoid diagonal clipping. Justify any...

Classical IP Over ATM DigitalTransmission

Thu, 09 Feb 2012 16:48:20 GMT

The classical IP over ATM CLIP model RFC 2255 is an IETF specification whereby IP treats ATM as another subnetwork to which IP hosts and routers are attached. In the CLIP model multiple IP subnetworks are typically overlaid on top of an ATM network. The part of an ATM network that belongs to the same IP subnetwork is called a logical IP subnetwork LIS , as shown in Figure 10.2. All members IP end systems in the same LIS must use the same IP address prefix e.g., the same network number and...

The Radiofrequency Amplifier CircuitDesign

Tue, 07 Feb 2012 15:32:58 GMT

The choice of an amplifier to boost the power coming out of the modulator to the level required to drive the antenna can be made when the following points have been considered 1 The amplifier must be linear so as to preserve the nature of the modulated signal. 2 The output power of the amplifier can vary from a few watts to hundreds of kilowatts. 3 A high conversion efficiency is a necessity when high power is a requirement. The portion of the dc power supplied to the amplifier which is not...

Calculation of IF Bandwidth and Peak Frequency Deviation SatelliteCommunications

Tue, 07 Feb 2012 10:58:28 GMT

2.6.4.1 IF Bandwidth. The IF of a FM receiver must accommodate the RF bandwidth, which consists of the total peak deviation spread and a number of generated sidebands. The IF bandwidth can be estimated from Carson's rule, where A Fp is the peak frequency deviation and Fm is the highest modulating frequency given in the middle column of Table 2.5. 2.6.4.2 Frequency Deviation. The value of AFp in equations 2.17 and 2.18 below is peak deviation. The peak deviation for a particular link should be...

Debugging Using VM Spy BluetoothTechnology

Sun, 05 Feb 2012 18:32:49 GMT

Debug output from the application can be viewed using the VM Spy utility.To begin using VM Spy, complete the following steps 1. Make sure the debugger isn't running, and nothing else is using the PC serial port. 2. Ensure the Casira serial cable is connected to the PC. 3. Make sure the Casira is configured to use BCSP. 6. Select the COM port and baud rate that match the Casira configuration. Figure 7.7 shows the VM Spy window this figure also shows the VM data window which is explained in the...

Contents 1 MeshNetworks

Sun, 05 Feb 2012 10:09:33 GMT

2.1.1 802.11 Mesh 2.1.2 Capacity 2.1.2.1 Single-radio, single-channel mesh networks a 2.1.2.2 Single-radio, multichannel mesh networks 55 2.1.2.3 Multiradio 2.2 Radio usage 2.3 Channel assignment and 2.3.1 Channel assignment 2.3.1.1 Interfering 2.3.2 Formulations and 2.3.2.1 Integer linear 2.3.2.2 Graph-theoretic 2.3.4 Routing

Introduction 1 Optical Fiber 2

Sat, 04 Feb 2012 07:48:27 GMT

As transmission moves closer to the user and distances become shorter, the impairments discussed above for long-haul and metro become less significant. A different set of solutions is necessary to address the specific needs of the local area network LAN market and those of other short-reach applications, such as storage area networks and equipment room interconnections. As demand for data rates in excess of a Gbps grows for these applications, multimode fiber MMF and short-wave VCSELs are...

Introduction Qja InformationSecurity

Fri, 03 Feb 2012 17:27:11 GMT

The development of information technology is particularly noticeable in the methods and techniques of data acquisition, high-performance computing, and bandwidth frequency. According to a newly observed phenomenon, called a storage low Fayyad amp Uthurusamy, 2002 , the capacity of digital data storage is doubled every 9 months with respect to the price. Data can be stored in many forms of digital media, for example, still images taken by a digital camera, MP3 songs, or MPEG videos from...

References Whg SatelliteCommunications

Thu, 02 Feb 2012 20:55:11 GMT

1. H. J. Liebe, Atmospheric Propagation Properties in the 10 to 75 GHz Region A Survey and Recommendations, ESSA Technical Report ERL 130-ITS 91, Boulder, CO, 1969. 2. Attenuation by Atmospheric Gases, ITU-R P.676-6, 2005. 3. D. C. Hogg, ''Millimeter-Wave Propagation Through the Atmosphere, Science, 1968. 4. R. K. Crane, Prediction of the Effects of Rain on Satellite Communications Systems,'' Proceedings of the IEEE, Vol. 65, pp. 456-474, 1977. 5. Recommendations and Reports of the CCIR, CCIR...

References Yhr SatelliteCommunications

Thu, 02 Feb 2012 15:24:45 GMT

1. General Engineering Beyond-Horizon Radio Communications, USAF T.O. 31Z-10-13, U.S. Department of Defense, Washington, DC, Oct. 1971. 2. Military Handbook Facility Design for Tropospheric Scatter Transhorizon Microwave System Design , MIL-HDBK-417, U.S. Department of Defense, Washington, DC, Nov. 1977. 3. P. L. Rice, A. C. Longley, K. A. Norton, and A. P. Barsis, Transmission Loss Prediction for Tropospheric Communication Circuits, NBS Tech. Note 101, U.S. National Bureau of Standards,...

References Psq Optical Fiber 2

Wed, 01 Feb 2012 16:54:50 GMT

Agarwal. G. P., 1995. Non-Linear Fiber Optics. 2nd ed. New York Academic Press. Alferness, R. C 1982. Waveguide electrooptic modulators, IEEE Trans. Microwave Theory Tech V MTT-30, pp. 1121-1137. Becker, R. A., and Kincaid, B. E., 1993. Improved electrooptic efficiency in guided wave modulators. J. Lightwave Tech., V 11, pp. 2076-2079. Burns, W. K., 1992. Shaping the digital switch. IEEE Photon. Technol. Lett V 4. pp. 861-863. Burns, W. K Klein, P. H West, E. J., and Plew, L. E 1979. Ti...

Crossbar Exchange SwitchingSystems

Wed, 01 Feb 2012 16:02:12 GMT

In the late 1930's and throughout 1940's, AT amp T introduced various versions of the crossbar switches. This crossbar switch basically consists line link frames trunk, link frames and common control equipments. With crossbar switchies and common control equipments, the crossbar exchange achieves full access and nonblocking capabilities. Active elements called crosspoints are placed between input and output lines. In common control switching systems, the switching and the control operations are...

R 0o pRcos 0o340 RadioWave

Tue, 31 Jan 2012 20:03:16 GMT

where p is the surface reflection coefficient, while Ri represents the incident power, and 0, is the observation angle. Phong Model. The reflection pattern is adequately represented with the Lambert model for a number of different rough surfaces. An exception however is the region of space in the vicinity of specular reflection here the diagram presents an important component which is not allowed for by the Lambert model. In the Phong model, the reflection diagram is considered as the sum of...

Topology Control Schemes For Multiradio Wireless Mesh Networks MeshNetworks

Mon, 30 Jan 2012 02:18:54 GMT

In WMNs, topology control refers to the alteration of network topology by modifying one or more parameters such as mobility, location, transmission power, directionality of antennas, and the status of network interfaces. This section presents the objectives of topology control and the existing solutions for topology control in WMNs. 1.9.1 Objectives of Topology Control Protocols The network capacity is influenced by the network topology and therefore, altering the topology can increase the...

Info Cdu SwitchingSystems

Fri, 27 Jan 2012 00:23:45 GMT

Touch tone dial telephone are introduced into market after field trials by AT amp T. In this section the telophone handset basic telephone circuits, rotary dial telephone, touch tone dial telephone, simple telephone circuits and its related topics and finally standards for the telephone are discussed. The telephone is a familiar end instrument in telecommunication system. The telephone is basically a transducer. Transducer is a device that converts one form of energy into a different form. The...

Reflector Antennas RadioEngineering

Wed, 25 Jan 2012 16:13:15 GMT

Reflector antennas are used as high-gain, narrow-beam antennas in fixed radio links, satellite communication, radars, and radio astronomy. A parabolic reflector antenna is the most common of reflector antennas. Figure 9.26 a shows a parabolic antenna fed from the primary focus. The equation of the surface is where F is the focal length. The rays coming from the focal point are converted parallel by the reflector or vice versa. A more physical interpretation is that the fields radiated by the...

Horn Antennas RadioEngineering

Wed, 25 Jan 2012 16:12:48 GMT

An open waveguide end operates as a simple antenna. It has a broad, unsym-metrical beam and a rather large impedance mismatch. A much better antenna, a horn antenna, is obtained by widening the waveguide end, as shown in Figure 9.23. H-plane, E-plane, and pyramidal horns are fed from a rectangular waveguide. An H-plane horn is widened along the broad side of the waveguide, an E-plane horn along the narrow side. A pyramidal horn is broadened in both directions. The distribution of the aperture...

Example 82 ImpulseResponse

Tue, 24 Jan 2012 20:57:09 GMT

There are many ways to translate data into binary equivalents. Example 8.1 showed one way to convert text into 4-PAM and then into binary. Another way exploits the Matlab function text2bin. m and its inverse bin2text. m, which use the 7-bit version of the ASCII code rather than the 8-bit version . This representation is more efficient, since each pair of text letters can be represented by 14 bits or seven 4-PAM symbols rather than 16 bits or eight 4-PAM symbols . On the other hand, the 7 bit...

Bending Refraction of Radio Waves in Troposphere RadioEngineering

Tue, 24 Jan 2012 19:07:07 GMT

The refraction index n yje of the troposphere fluctuates over time and location. In normal conditions the refraction index decreases monotonically versus altitude, because the air density decreases. Because a phenomenon of this kind is a weak function of altitude, it causes slow bending of the ray. Fast changes in the refraction index cause scattering and reflections. Turbulence, where temperature or humidity differs strongly from those of the surroundings, gives rise to scattering. Reflections...

Opamp Hyt TelecommunicationCircuits

Tue, 24 Jan 2012 03:05:25 GMT

1. Design a first-order filter with a gain of 10 and a cut-off frequency of 200 Hz. Use a 0.05 F capacitor. 2. Design a second-order 1 dB ripple high-pass Chebyshev filter with a gain of 2 and a cut-off frequency of 500 Hz. 3. Draw the response of a low-pass second-order Butterworth filter having a gain of unity and a cut-off frequency of 1.5 kHz. Also on the same sketch estimate the response of a fourth-order low pass filter of the Butterworth type having the same gain and cut-off frequency....

or for JLsa ImpulseResponse

Sun, 22 Jan 2012 15:39:55 GMT

0 1000 000 3000 4000 5000 8000 7000 8000 3000 1 0000 0 1000 000 3000 4000 5000 8000 7000 8000 3000 1 0000 0 1000 ZKJO 3000 4000 5000 6000 7000 8000 9000 10000 0 1000 ZKJO 3000 4000 5000 6000 7000 8000 9000 10000 0 1000 2000 3000 4000 5000 6000 70110 8000 9000 10W0 FIGURE 6.13 An automatic gain control adjusts the parameter a in the top panel automatically to achieve the desired output power. Perhaps the best way to formally describe how the algorithms work is to plot the performance functions....

Problems 1 ImpulseResponse

Sat, 21 Jan 2012 21:21:17 GMT

6.15. Explore the behavior of steepest descent by running polyconverge .m with different a Try mu -.01, 0, .0001, .02, .03, .05, 1.0, 10.0. Can mu be too large or too small b Try N 5, 40, 100, 5000. Can N be too large or too small c Try a variety of values of x l . Can x l be too large or too small As an alternative to simulation, observe that the process 6.6 is itself a linear time invariant system, of the general form which is stable as long as a lt 1. For a constant input, the final value...

Info Dau SatelliteCommunications

Sat, 21 Jan 2012 19:24:36 GMT

12.25 effectively, we need to know the gyrofrequency for the region of interest. We can derive this value from Figure 12.26. Example 3. A certain HF path operates during a sunspot number 100, the operating frequency is 18 MHz, and the elevation or TOA is 10 . Calculate the D-layer absorption value for 12 noon local time at midpath for the Figure 12.25. Nomogram for obtaining the ionospheric absorption per hop from the absorption index I, the effective wave frequency f fH, and the angle of...

Diversity A Technique to Mitigate the Effects of Fading and Dispersion VoiceChannels

Thu, 19 Jan 2012 22:36:03 GMT

18.4.2.1 Scope. We discuss diversity to reduce the effects of fading and to mitigate dispersion. Diversity was briefly covered in Section 9.2.5 where we dealt with LOS microwave. In that section we discussed frequency and space diversity. In principle, such techniques can be employed either at the base station and or at the mobile unit, although different problems have to be solved for each. The basic concept behind diversity is that two or more radio paths carrying the same information are...

Shortwave Radio CircuitDesign

Thu, 19 Jan 2012 20:36:15 GMT

Frequencies between 3 MHz and 30 MHz are set aside for use in long distance radio communication. This frequency band is generally referred to as the short-wave band. The wavelength that lies between 1 m and 100 m is short compared to that of the medium wave. It was pointed out in Section 2.9 that the increased frequency of the carrier used in short-wave communication gives its electromagnetic transmission wave increasingly directional properties. Transmission antennae can be designed to...

Info Uss SatelliteCommunications

Thu, 19 Jan 2012 16:51:40 GMT

aAt 20 GHz the specific attenuation A 0.006 fl 12 dB km and for Rosman, NC, the effective path length is 5.1 km to ATS-6. bFor a ground temperature of 17 C 63 F, the Tm 275 K. Source Reference 16. aAt 20 GHz the specific attenuation A 0.006 fl 12 dB km and for Rosman, NC, the effective path length is 5.1 km to ATS-6. bFor a ground temperature of 17 C 63 F, the Tm 275 K. Source Reference 16. Example 3. From Table 9.6 with a total rain attenuation of 11 dB, what is the sky noise at 20 GHz Assume...

Error handling IPMultimedia

Thu, 19 Jan 2012 16:16:13 GMT

Diameter errors fall into two categories protocol errors and application errors. Protocol errors occur at the base protocol level and are treated on a per-hop basis e.g., errors in message routing may direct a downstream agent to take special action . Application errors are generated due to problems with specific Diameter applications. When a request message generates a protocol error an answer message is sent back with the E bit set in the Diameter header, indicating a protocol error. The...

Ccitt No 5 Signaling 85 Iscb SignalingSystems

Thu, 19 Jan 2012 16:04:26 GMT

Switchblock TC4 TC4 Switchblock Figure 4.3-1 Supervision Signals of CCITT No. 5. a signal on send channel at ISC-A. b signal on receive channel at ISC-A. Signaling Frequencies. Two in-band signaling frequencies are used , 2400 Hz, and 2 is 2600 Hz. There are three signals ,, 2, and a composite signal that contains , and 2. Signaling Circuitry in Trunk Circuits. The functions and circuitry for supervision signaling in the TC4 circuits of analog CCITT No.5 trunks are similar to those discussed in...

Figure 915 Star and PeertoPeer Topologies Wireless Networks 2

Thu, 19 Jan 2012 15:22:44 GMT

In a star topology data may be exchanged only between the network coordinator and the DEVs or network nodes no direct communication between DEVs . There are two types of communication uplink, from the DEVs to the network coordinator and downlink, from the network coordinator to the DEVs. In a peer-to-peer topology, each DEV can communicate with others within its radio range. There is no network coordinator. However, a DEV can become such a coordinator if it is the first device to communicate on...

OMA PoC Release 2 MultimediaTelephony

Thu, 19 Jan 2012 12:31:16 GMT

As the cellular networks evolve, they will be able to provide other more advanced IP-based real-time services than the plain voice services offered in the OMA PoC Release 1 specifications. Advanced services should, in this context, be seen as services that are more demanding in terms of bit rate and delay, and that offer improved possibilities of person-to-person communication and thus increase perceived user value compared to a plain voice call. OMA is trying to make use of the new...

Info Tle Signaling Systems 2

Thu, 19 Jan 2012 10:10:07 GMT

Send Called Address Called Address Messages Change Power Order Change Power Confirmation Registration Confirmation Registration Initial Voice Channel Designation Handoff message Source EIA TIA 553. Reproduced with permission of TIA. ORDQ Order Qualifier. This field is included in all messages that have an ORD. In most messages, ORDQ is not used and is coded 000. In the change power order and its confirmation, ORDQ holds the mobile attenuation code that specifics the transmit power Section...

Figure 1134 RRC Connection Establishment Procedure Wireless Networks 2

Thu, 19 Jan 2012 07:34:14 GMT

Figure 11.35 illustrates the radio bearer establishment procedure. The radio bearer establishment procedure is initiated when the upper layers in the mobile station need to set up the transport and physical channels to accommodate the traffic flow from the upper layers. This procedure starts after the UTRAN performs the admission control and selects the parameters for the transport i.e., transport format set and physical i.e., channelization coding channels. 11.6.2.2 Radio Bearer Establishment...

Interleaving MobileStations

Wed, 18 Jan 2012 20:33:31 GMT

The decoding result of the convolutional code strongly depends on the frequency and grouping of bit errors that occur during transmission. Especially burst errors during long and deep fading periods, i.e. a series of erroneous sequential bits, have negative impact on error correction. In such cases, the channel is not a binary channel without memory, rather the single-bit errors have statistical dependence, which diminishes the result of the error correction procedure of the convolutional code....

Contributors BluetoothTechnology

Wed, 18 Jan 2012 20:04:01 GMT

David Kammer has been involved with the handheld industry since 1997. David is currently the Technical Lead for Bluetooth technologies at Palm Inc., and is one of the authors of the original Bluetooth specification. Before working on Bluetooth, David worked on IR technology, and on the Palm VII. In addition to his work at Palm, he also consults for several companies, including In2M and Microsoft, in the field of wireless communications and PalmOS programming. David has spoken at a number of...

Gigabit Ethernet DigitalTransmission

Wed, 18 Jan 2012 19:49:17 GMT

The IEEE 802.3z Gigabit Ethernet standard was completed in 1998 and established an Ethernet LAN that increased the transmission speed over that of Fast Ethernet by a factor of 10. The goal was to define new physical layers but to again retain the frame structure and procedures of the 10 Mbps IEEE 802.3 standard. The increase in speed by another factor of 10 put a focus on the limitations of the CSMA-CD MAC algorithm. For example, at a 1 Gbps speed, the transmission of a minimum size frame of 64...

Figure 813 Paging Sequences Wireless Networks 2

Wed, 18 Jan 2012 18:34:07 GMT

In Standby, no connection has been established and the station can use all of its capacity to support Page Scan. If desired, the station can place ACL connections in the Hold mode or even use the Park mode before entering Page Scan. SCO connections are preferably not interrupted by Page Scan. In this case, Page Scan may be interrupted by the reserved SCO slots which have higher priority than Page Scan. At the connection state, a Bluetooth station becomes the member of a piconet. The station can...

Effective Length Average Height and Radius of Meteor Trails SatelliteCommunications

Wed, 18 Jan 2012 18:16:10 GMT

Consider the ray geometry for a meteor burst propagation path as shown in Figure 13.7 between transmitter T and receiver R. P represents the tangent point and P' a point further along the trail such that R1 R'2 exceeds R1 R2 by half a wavelength. Thus PP' of length L lies within the principal Fresnel zone and the total length of the trail within this zone is 2L. Provided R1 and R2 are much greater than L, it follows that 5 angle between the trail axis and the plane of propagation A wavelength...

Asynchronous Vs Synchronous Vs Isochronous PacketSwitched

Wed, 18 Jan 2012 18:15:46 GMT

Now we need to deal with the issue of synchronization, or timing. This requires synchronizing the transmitting and receiving devices. When I think of synchronization, I think of dancing, because if you and your partner are out of step, then disaster ensues. Fred Astaire and Ginger Rogers were dance partners that were always in step, or synchronized. Communications devices work the same way. There is bit, character byte , and message block frame packet synchronization that must occur before data...

Transmission Kdc DigitalTransmission

Wed, 18 Jan 2012 16:50:40 GMT

Each time the client wishes to access a particular server, it sends a request to the KDC along with the TGT and the server's name. The KDC decrypts the TGT to recover the session key. The KDC then returns a ticket to the client that allows access to the desired server. Public key systems require only one pair of keys per user, but they still face the problem of how the public keys are to be distributed. Because an imposter can advertise certain public keys as belonging to other parties, the...

Figure 57 MAC Frame Structure for Sectored Antennas Wireless Networks 2

Wed, 18 Jan 2012 13:37:37 GMT

The MAC frame consists of Broadcast Channel BCH duration, Frame Control Channel FCH duration, Access Feedback Channel ACH duration and at least one Random Channel RCH duration. If there is transmission between the AP CC and the MTs, the Downlink DL phase and or Uplink UL phase are included in the MAC frame. If there is transmission among the MTs direct mode , the Direct Link DiL phase is also included. The BCH duration is fixed. The duration of the FCH, DL, DiL, and UL phases and the number of...

Tcp 302 DigitalTransmission

Wed, 18 Jan 2012 11:50:25 GMT

timing recovery 300, 335, 645 Burst error model 157, 166-67, 176-77, 293 Bursty 21, 22, 29, 313-14, 318, 322, 340-41, 347, 380, 382, 396, 450, 466, 503-04, 628, 638-39 Busy hour 233 C language programs 72-79, 160 Cable modem 143, 344 Cable television CATV 2, 31, 33, 42, 110, 140-43, 195, 253, 258 CAIDA 86, 93 Care-of address 589-90 Carried load 824 Carrier sensing 26, 359, 361, 427, 450 Carrier sensing multiple access CSMA 359-61, 365, 425, 428, 454 Carrier sensing multiple access with...

Problems And Exercises Wsv SatelliteCommunications

Wed, 18 Jan 2012 10:47:54 GMT

1 Above 10 GHz, there are two additional degradations to path loss that we must take into account. What are they 2 There are two frequency bands between 10 and 100 GHz that display high attenuation due to atmospheric gases. What bands are these Which one displays excessively high attenuation, making it unusable for most earth-bound applications. 3 Discuss two practical applications of the high-loss band in question 2. 4 Argue why cumulative annual rainfall rates may not be used for calculation...

Basic Properties of Digital Transmission Systems DigitalTransmission

Wed, 18 Jan 2012 09:40:50 GMT

The purpose of a digital transmission system is to transfer a sequence of 0s and Is from a transmitter on the left end to a receiver on the right as shown in Figure 3.10. We are particularly interested in the bit rate or transmission speed as measured in bits second. The bit rate R can be viewed as the cross-section of the information pipe that connects the transmitter to the receiver. The transmission system uses pulses or sinusoids to transmit binary information over a physical transmission...

The TISPAN Next Generation Network MultimediaTelephony

Wed, 18 Jan 2012 07:44:38 GMT

Figure 3.23 The TISPAN NGN architecture. Figure 3.23 The TISPAN NGN architecture. ETSI TISPAN has developed an architecture to provide multimedia services over fixed accesses. This architecture is called Next Generation Network NGN and is based on the IMS. NGN is an access agnostic architecture able to provide IMS services to users using any type of access. This way, users can enjoy the same set of services regardless of the access they use. Therefore, TISPAN NGN achieves the much expected...

TCP Reliable Stream Service DigitalTransmission

Wed, 18 Jan 2012 05:52:31 GMT

The Transmission Control Protocol TCP provides a logical full-duplex two-way connection between two application layer processes across a datagram network. TCP provides these application processes with a connection-oriented, reliable, in-sequence, byte-stream service. TCP also provides flow control that allows receivers to control the rate at which the sender transmits information so that buffers do not overflow. TCP can also support multiple application processes in the same end system.6 Before...

Standing wave ratio TelecommunicationCircuits

Wed, 18 Jan 2012 05:34:02 GMT

Standing waves have already been mentioned, together with their formation due to load termination. Figure 7.4 shows the result of producing standing waves on a transmission line. Remember that standing waves are produced when two waves having the same frequency and amplitude and travelling in opposite directions are superimposed. The figure shows that standing waves produce points of minimum and maximum disturbance called nodes and antinodes, and this applies to voltage or current waves....

Simulating The Ideal System ImpulseResponse

Tue, 17 Jan 2012 23:01:05 GMT

The simulation of the digital communication system in Figure 9.1 divides into two parts just as the figure does. The first part creates the analog transmitted signal, and the second part implements the discrete-time receiver. The message consists of the character string 01234 I wish I were an Oscar Meyer wiener 56789 In order to transmit this important message, it is first translated into the 4-PAM symbol set 1, 3 which is designated m i for i 1,2, , N using the subroutine letters2pam. This can...

magnitude spectrum shows the frequency content of the output signal ImpulseResponse

Tue, 17 Jan 2012 20:12:22 GMT

FIGURE 3.1 The element transforms the input signal x into the output signal y. The action of an element can be thought of in terms of its effect on the signals in time, or via the Fourier transform in terms of its effect on the spectra of the signals. Readers who have studied signal and systems often required in electrical engineering degrees , will recognize that the time domain representation of a signal and its frequency domain representation are related by the Fourier transform, which is...

The Home Subscriber Server and the Subscription Location Function MultimediaTelephony

Tue, 17 Jan 2012 20:10:26 GMT

The Home Subscriber Server HSS is a database that stores the profile of all the users of a domain. A user's profile includes security-related information such as cryptographic keys, service-related information such as to which services the user is subscribed, and other information such as the S-CSCF that has been allocated to the user or the user's location. An HSS is supposed to be a central database for a domain. However, some networks have more users than a single HSS can handle. These...

Info Oqj SatelliteCommunications

Tue, 17 Jan 2012 09:44:21 GMT

Figure 6.22. Ku-band frequency polarization plan for Galaxy VII. From Ref. 27. Figure 6.23. Ku-band EIRP contours in qdBW for Galaxy VII, 91 W longitude for vertical polarization. Figure 6.23. Ku-band EIRP contours in qdBW for Galaxy VII, 91 W longitude for vertical polarization. G T - - SFD 87.4 7 dB COMMANDABLE STEP ATTENUATION G T - - SFD 87.4 7 dB COMMANDABLE STEP ATTENUATION Figure 6.24. Ku-band saturation flux density SFD contours for Galaxy VII, 91 W longitude for horizontal...

Propagation Effects With A Low Elevation Angle SatelliteCommunications

Tue, 17 Jan 2012 09:42:19 GMT

As the elevation angle of an earth terminal is lowered, the ray beam penetrates an ever increasing amount of atmosphere. Below about 10 , fading on the downlink signal must be considered. Fading or signal fluctuations apply only to the ground terminal downlink because its antenna is in close proximity to a turbulent medium. The companion uplink satellite path will suffer uplink fluctuation gain degradation only due to scattering of energy out of the path Ref. 16 . Because of the large distance...

CELP Speech Codecs MultimediaTelephony

Tue, 17 Jan 2012 09:20:44 GMT

Most modern speech codecs are based on the Codebook Excited Linear Predictive CELP codec model 49 , where speech is synthesized according to a model of how the speech is produced by humans. The synthesis, in the decoder, follows the following steps 1. A fixed code book generates an innovation. This simulates the air flow created by the lungs. 2. The innovation is passed through a pitch predictor, which is also often called adaptive code book. This creates pitch pulses in a similar way as the...

WiMAX Simulator MeshNetworks

Tue, 17 Jan 2012 09:12:14 GMT

Figure 13.13 illustrates the protocol structure of the WiMAX mesh MAC protocol stack. One of the functionalities of the mesh network entry protocol component is selection of sponsor node, which will involve communication exchange of unicast MSH-NENT from the new entry node and broadcast MSH-NCFG control messages from Figure 13.13 WiMAX mesh simulator protocol structure. Figure 13.13 WiMAX mesh simulator protocol structure. the sponsor node. In the design, the network entry process has been...

VIRTUAL LANs PathOptimization

Mon, 16 Jan 2012 22:52:53 GMT

Virtual LANs provide support for workgroups. A LAN consists of one or more LAN segments, and hosts on the same LAN segment can communicate directly through Layer 2 link layer without a router between them. These hosts share the same Layer 3 network layer subnet address, and communication between the hosts of one LAN segment remains in this segment. Thus Layer 3 network layer subnet address forms a broadcast scope that contains all hosts on the LAN segment. The workgroups are groups of hosts...

Eirp 1 SatelliteCommunications

Mon, 16 Jan 2012 20:03:20 GMT

MBC transmission loss Receiver antenna gain 73 dBm -180 dB 13 dB -94 dBm 107 dBm 13 dB occurring, of course, toward the end of a trail's useful life. Coding with appropriate interleaving is one method of mitigating these multipath effects. D-layer absorption often is neglected in link budget analyses of meteor burst links. We discuss D-layer absorption and its calculation in Chapter 12. Another source is CCIR Rep. 252-2 Ref. 10 . D-layer absorption, a daytime-only phenomenon, may exceed 3 dB at...

Architecture Wireless Networks 2

Mon, 16 Jan 2012 16:26:52 GMT

The standard addresses two topologies ad hoc topology, referred to as Independent Basic Service Set IBSS , and infrastructure topology, referred to as Basic Service Set BSS . A topology that combines several BSS cells is referred to as Extended Service Set ESS . As shown in Figure 4.2, an ad hoc network or an IBSS consists of stations within mutual communication range of each other via the wireless medium. Such a network is created spontaneously, without preplanning, for ad hoc temporary...

Final and Intermediate GT Translations SignalingSystems

Mon, 16 Jan 2012 13:56:46 GMT

In the above example, SCCP-E makes a final GT translation, which yields the PC SSN address of destination R800-D. This is possible because an SCCP in a signal transfer point has the necessary data to perform final translations for all destinations in its network, and we have assumed that all entities in Fig. 14.3-4 are in the same network. When the originating and destination ASEs are in different networks, the SCCPs in the originating network have no data to do final GT translations. In this...

Source Coding and Speech Processing MobileStations

Mon, 16 Jan 2012 12:41:42 GMT

Source coding reduces redundancy in the speech signal and thus results in signal compression, which means that a significantly lower bit rate is achieved than needed by the original speech signal. The speech coder decoder is the central part of the GSM speech processing function, both at the transmitter Figure 6.2 as well as at the receiver Figure 6.3 . The functions of the GSM speech coder and decoder are usually combined in one building block called the codec COder DECoder . Figure 6.2...

Signaling Interfaces and Protocols Signaling Systems 2

Mon, 16 Jan 2012 11:01:38 GMT

The interfaces and protocols for signaling between a MS and the PLMN are shown in Fig. 12.7-2 10 . ETSI has defined two interfaces the Um radio interface between a MS and the BSS, and the A cable interface between BSS and MSC. This is different from the U.S. cellular systems AMPS, IS-54 , where it is assumed that a MSC and its associated base stations BSs are supplied by the same manufacturer, and that the MSC-to-BSS interface is an internal manufacturer-specific interface. The A-interface...

Applications Of Perfluorinated Plastic Fiber Optical Fiber 2

Mon, 16 Jan 2012 05:13:24 GMT

The raison d' tre for PFBVE GI-POF is to qualitatively simplify field installation of high-speed data links, especially in the gigabit-per-second regime. In comparison to silica-based optical fibers, GI-POF eliminates the need for trained installers and specialized cleaving and polishing tools. In comparison to high-speed unshielded twisted-pair UTP copper links, GI-POF simplifies the cable pulling and termination aspects of the installation process. As with all optical media, GI-POF also...

Common Channel Signalling SwitchingSystems

Sun, 15 Jan 2012 18:41:03 GMT

Introduction of SPC digital switching systems with high speed processors in the telecom network has necessiated modernisation of signalling. Also, in order to meet the transfer of varieties of informations for call management and network management and to satisfy the subscribers requirement on various features, the uninterrupted, high speed signalling has become inevitable. The rapid dvelopment of digital systems paved way for the new signalling system called common channel signalling. Instead...

TDMA System Clocking Timing and Synchronization It was SatelliteCommunications

Sun, 15 Jan 2012 14:15:25 GMT

previously stressed that an efficient TDMA system must have no burst overlap, on the one hand, and as short a guard time as possible between bursts, on the other hand. We are looking at guard times in the nanosecond regime. The satellites under discussion here are geostationary. For a particular TDMA system, the range to a satellite can vary from 23,000 to 26,000 statute miles. We can express these range values in time equivalents by dividing by the velocity of propagation in free space or...

Numbering Plan For International Signaling Point Codes VoiceChannels

Sun, 15 Jan 2012 03:24:03 GMT

The number plan described in ITU-T Rec. Q.708 Ref. 12 has no direct relationship with telephone, data, or ISDN numbering. A 14-bit binary code is used for identification of signaling points. An international signaling point code ISPC is assigned to each signaling point in the international signaling network. The breakdown of these 14 bits into fields is shown in Figure 14.8. The assignment of signaling network codes is administered by the ITU Telecommunication Standardization Sector previously...

Vswr 10 SatelliteCommunications

Sun, 15 Jan 2012 00:28:50 GMT

Ambient Temperature 24 C 75 F Atmospheric pressure, dry air Figure 15.9. Loss versus frequency for air dielectric coaxial cable. Courtesy of the Andrew Corporation Ref. 7. There are a number of important parameters to be considered for the application of coaxial cable as a transmission line. Probably the most important for the system engineer is attenuation or loss as shown in Figures 15.8 and 15.9. Loss varies with ambient temperature. The reference value in the figures is 24 C 75 F . Figure...

Correlation ImpulseResponse

Sat, 14 Jan 2012 23:36:11 GMT

Suppose there are two signals or sequences. Are they similar, or are they different If one is just shifted in time relative to the other, how can the time shift be determined The approach called correlation shifts one of the sequences in time, and calculates how well they match by multiplying point by point and summing at each shift. When the sum is small then they are not much alike when the sum is large, many terms are similar. Thus correlation is a simple form of pattern matching, which is...

Datagram Approach DivisionMultiplexing

Sat, 14 Jan 2012 13:31:07 GMT

In the datagram approach to packet switching, each packet is treated independently from all others. Even when one packet represents just a piece of a multipacket transmission, the network and network layer functions treats it as though it existed alone. Packets in this technology are referred Figure 9.2-2 shows how the datagram approach can be used to deliver four packets from station A to station X. In this example, all four packets or datagrams belong to the same message but may go by...

LOWER LAYERS 2231 ATM Layer Signaling Systems 2

Sat, 14 Jan 2012 02:53:35 GMT

The ATM layer is responsible for cell formatting. An ATM cell consists of a 5-byte header and a 48-byte information field, for a total of 53 bytes. The size of the information field is the result of a compromise reached at the then CCITT between European and North American proposals. Both sides wanted a short cell for speed and efficiency, but Europeans advocated a 32-byte payload, while North Americans favored a 64-byte payload so it was agreed to split the difference. The header contains the...

Introduction Ecs InformationSecurity

Fri, 13 Jan 2012 16:14:58 GMT

The world continues to be driven by the rapid development of information technology and globalization. Not surprisingly, the working environments that have been projected to grow the fastest are all related to the usage of computers, the Internet, and information systems. With globalization, many multinational corporations MNCs are increasingly employing virtual teams VTs . It was reported that 137 million workers worldwide are involved in some form of remote electronic work Solomon, 2001 ....

ReverseBattery Signaling NetworkManagement

Fri, 13 Jan 2012 14:27:24 GMT

Reverse-battery signaling employs basic methods 1 and 2 above, and it takes its name from the fact that battery and ground are reversed on the tip and ring to change the signal toward the calling end from on hook to off hook. Figure 4.12 shows a typical application of reverse-battery signaling in a common-control switch. In the idle or on-hook condition, all relays are unoperated and the switch SW contacts are open. Upon seizure of the outgoing trunk by the calling switch exchange trunk group...

PNNI Routing Protocol Signaling Systems 2

Fri, 13 Jan 2012 11:04:05 GMT

Before addressing the signaling part of the PNNI protocol, a few words about the PNNI routing protocol are needed, since it plays a role that affects connection setup. Routing protocols are a basic function of packet networks and are used by Layer 3 nodes, such as routers, to exchange reachability and link status information without manual intervention. That exchange of information is done so that a route path from the source to the destination can be determined at all times, as nodes and links...

Scheduling MSHNENT in Control Subframe MeshNetworks

Fri, 13 Jan 2012 02:40:49 GMT

In the mesh mode, transmission opportunities in the control subframe and minislots in the data subframe are separated. Each node competes the control channel access. The contention consequence in the control subframe does not have effect on the data transmission during the data subframe of the same frame. There are two different messages in the control subframes MSH-NENT and MSH-NCFG. Accordingly, there are two scheduling algorithms defined for these two messages. In this section, we will...

Routing and Wavelength Assignment for Primary Lightpath LargeScale

Thu, 12 Jan 2012 22:00:35 GMT

For each new lightpath setup request, the LMN first solves the routing and wavelength assignment problem for the primary lightpath. The primary lightpath is selected from among the free wavelengths, and the wavelengths being used for backup. If there is a lightpath having the same source-destination pair as the new lightpath, the new lightpath is set up along the same route as the existing lightpath. This is because in IP over WDM networks, the IP layer recognizes that paths on different routes...

References Qsr SensorNetworks

Thu, 12 Jan 2012 17:16:51 GMT

1. S. Adlakha and M. Srivastava, Critical density thresholds for coverage in wireless sensor networks, IEEE Wireless Commun. Networking, 3, 16-20, March 2003. 2. M. Cardei, D. MacCallum, X. Cheng, M. Min, X. Jia, D. Li, and D.-Z. Du, Wireless sensor networks with energy efficient organization, J. Interconnection Networks, 3 3-4 , 213-229, Dec 2002. 3. M. Cardei and D.-Z. Du, Improving wireless sensor network lifetime through power aware organization, accepted to appear in ACM Wireless Networks....

The Human Voice VoiceChannels

Thu, 12 Jan 2012 16:17:33 GMT

Human voice communication depends on the voice-generating mechanism of mouth and throat being the initial transmitter, with the acuity of the ear being the receiver. Frequency components of the human voice extend down to some 20 Hz and as high as 32,000 Hz. The lower frequency components carry the voice energy and the higher frequency components carry emotion. Figure 5.1 shows a distribution of energy and emotion of the typical human voice. The human ear and many devices and components of the...

Info Hwz SatelliteCommunications

Thu, 12 Jan 2012 15:35:05 GMT

aGeneral allocation to PCS, licensees may use PACS. Source Table 2, p. 35 Ref. 19 . aGeneral allocation to PCS, licensees may use PACS. Source Table 2, p. 35 Ref. 19 . Figure 10.26. Scenario for PCS within IMT-2000 terrestrial component. From Ref. 28 Figure 1, p. 8, ITU-R M.687-2, 1997. Figure 10.26. Scenario for PCS within IMT-2000 terrestrial component. From Ref. 28 Figure 1, p. 8, ITU-R M.687-2, 1997. 10.11 FUTURE PUBLIC LAND MOBILE TELECOMMUNICATION SYSTEM FPLMTS FPLMTS is a cellular PCS...

Antimony Silica Tes Optical Fiber 2

Thu, 12 Jan 2012 14:52:08 GMT

In 1997, one of us Ellison found that erbium in antimony silicate glass Sb Si exhibited promising 1530 nm spectroscopy, appearing to be at least comparable to well-optimized tellurite glasses. A major effort was undertaken to convert compositions in this system into low-loss optical fibers for use in amplifiers and lasers. Antimony silicates make high-quality, low-loss fiber and can accommodate high levels of rare earth elements without significant clustering, but have lower refractive than...

Sacch Signaling Systems 2

Thu, 12 Jan 2012 10:17:32 GMT

Figure 12.8-2. Call originated by MS. From GSM 04.08 Version 4.10.0. Courtesy of ETSI. Section 12.9.1 . The network then assigns a SDCCH and returns an IMMEDIATE ASSIGNMENT message Section 12.9.1 . At this point, the MS and BSS tune their transmitter and receiver to the SDCCH. The MS next sends a CM SERVICE REQUEST Section12.9.2 , indicating that it wishes to originate a call. The network then decides whether to execute or skip the MS authentication. If the MS has ciphering capability, they...

Basic Packet Mode MobileStations

Thu, 12 Jan 2012 08:38:55 GMT

Two variants of PSPDN access can be realized with the protocol model in Figure 9.14 PSPDN access according to ITU-T X.32 Access to PSPDN packet handlers according to ITU-T X.31 Case A basic packet mode . PSPDN access according to X.32 has not met much acceptance with the applications the X.31 procedure is used more often. PSPDN access according to X.32 is the simpler variant. The X.25 packets can be trans Figure 9.14 X.25 access at the ISDN S interface Figure 9.14 X.25 access at the ISDN S...

Digital Los Microwave Terminals SatelliteCommunications

Thu, 12 Jan 2012 01:28:03 GMT

Figure 15.3 is a functional block diagram of a typical digital microwave radio terminal. Starting from the bottom of the figure on the transmit side left side , there are a number of baseband processing conditioning functions. The line code converter takes the standard PCM line codes e.g., DS1, DS3, E1, E2, E3, etc. , which have been implemented for good baseband transmission properties over wire systems, and converts the code, usually to a NRZ format. The resulting code is then scrambled by...

Info Qcm SwitchingSystems

Wed, 11 Jan 2012 23:03:00 GMT

A subscriber can be able to talk with or send data to someone in any part of the world almost instently and an exchange is able to set path and clear it after the conversation instantly by an effective signalling system. A signalling system link the variety of switching system, transmission systems and subscriber equipments in a telecommunication network to enable the network to function as a whole. The signalling are classified according to the internal signalling of an exchange, signalling...

Component Specification for Data Extraction and Loading WirelessNetworks

Wed, 11 Jan 2012 22:54:35 GMT

In the selection and pre-processing phases of KDD, various data sources must be identified and the underlying data must be captured in machine-readable format. The approach taken in this work is to perform a component-mediated step that collects heterogeneous data and populates that data in several relational database tables using traditional approaches i.e., existing data transformation techniques are embedded in component Chawathe et al., 1994 Nodine, Fowler, Ksiezyk, Perry, Taylor, amp...

G Ncs SatelliteCommunications

Wed, 11 Jan 2012 22:51:41 GMT

where y is the effective noise temperature of each amplifier or device and G is the numeric equivalent of the gain or loss of the device. Example 8. Compute Tr for the first three stages of a receiving system. The first stage is a LNA with a noise figure of 1.1 dB and a gain of 25 dB. The second stage is a lossy transmission line with 2.2-dB loss. The third and final stage is a postamplifier with a 6-dB noise figure and a gain of 30 dB. Frequency 12 GHz Figure 6.10. Example earth station...

GPRS entities IPMultimedia

Wed, 11 Jan 2012 18:24:07 GMT

The Serving GPRS Support Node SGSN links the RAN to the packet core network. It is responsible for performing both control and traffic-handling functions for the PS domain. The control part contains two main functions mobility management and session management. Mobility management deals with the location and state of the UE and authenticates both the subscriber and the UE. The control part of session management deals with connection admission control and any changes in the existing data...

Figure 1012 52Multiframe for PDCHs Wireless Networks 2

Wed, 11 Jan 2012 14:56:59 GMT

fiarne used tor irim Fra rr SO - l 1 Kad Slocks 1 dio WkK PTCCH . id I-rarne tmh T MA hmn fiarne used tor irim Fra rr SO - l 1 Kad Slocks 1 dio WkK PTCCH . id I-rarne tmh T MA hmn A PDCH is defined by a combination of a radio frequency channel and a time slot. On a radio frequency channel, PDCHs can be represented logically as eight physical channel instances see Figure 10.13 . The PDCH number presented here corresponds to the time slot number of the TDMA frame i.e., PDCH1 and time slot 1

FrequencyDivision Multiplexing Signaling Systems 2

Wed, 11 Jan 2012 14:18:30 GMT

Frequency-division multiplexing FDM 4,5 is a technique to carry the signals of a group of n analog four-wire trunks on a common four-wire analog transmission system. In each direction of transmission, the bandwidth of the transmission system is divided into n 300-3400 Hz channels, spaced at intervals of 4 kHz, for a total bandwidth of n x 4 kHz Fig. 1.4-5 . Figure 1.4-6 shows a group of n FDM trunks between exchanges X and Y. In this example, the trunks appear at the exchanges as two-wire...

Info Hag SatelliteCommunications

Wed, 11 Jan 2012 12:26:12 GMT

2.2 Initial Planning and Site Selection, 38 2.2.1 Requirements and Requirements Analyses, 38 2.2.2 Route Layout and Site Selection, 40 2.3.1 Determiniation of Median Value for -Factor, 46 2.6.2 Unfaded Signal Level at the Receiver, 55 2.6.3 Receiver Thermal Noise Threshold, 58 2.6.4 Calculation of IF Bandwidth and Peak Frequency Deviation, 61 2.6.5 Pre-emphasis De-emphasis, 64 2.6.6 Calculation of Median Carrier-to-Noise Ratio Unfaded , 67 2.6.7 Calculation of Antenna Gain, 69 2.7 Fading,...

Conclusion Jwt IntegratedCircuits

Wed, 11 Jan 2012 11:22:33 GMT

A 2.7 V radio transceiver for 900 1900 MHz was realized in a 50 GHz fT silicon germanium technology. The single chip transceiver contains the RX mixers, TX mixers, quadrature generator, amplifiers, quadrature phase shifters, the VCO and the 64 65 prescaler. Most of the circuits were realized in a 20 GHz bipolar technology before. In the 50GHz SiGe technology the noise figure was improved with 2dB and the additional bandwidth allows for true dual mode operation with identical gain curves for...

Problems And Exercises Hqz SatelliteCommunications

Wed, 11 Jan 2012 05:02:55 GMT

1 Define EMC and name and discuss its two subsets. 2 Name at least three measures we can take at the outset to reduce interference and its effects on with radio systems. 3 One area of concern is a receiver's IF. With careful frequency planning, we avoid three frequencies referenced to the IF. What are they 4 LOS microwave and satellite communication systems share the same frequency bands. A satellite communication transponder sprays the earth with RF energy. What did we learn prior to this...

Signal stabilitybased adaptive routing PathOptimization

Wed, 11 Jan 2012 01:33:30 GMT

Signal Stability-Based Adaptive Routing SSA is a variant of the AODV protocol to take advantage of information available at the link level. Both the signal quality of links and link congestion are taken into consideration when finding routes. It is assumed that links with strong signals will change state less frequently. By favoring these strong signal links in route discovery, it is hoped that routes will survive longer and the number of route discovery operations will be reduced. Link signal...

External Error Protection Block Coding MobileStations

Tue, 10 Jan 2012 19:58:42 GMT

The block coding stage in GSM has the purpose of generating parity bits for a block of data, which allow the detection of errors in this block. In addition, these blocks are supplemented by fill bits tail bits to a block length suitable for further processing. Since block coding is the first or external stage of channel coding, the block code is also known as external protection. Figure 6.7 gives a brief overview showing which codes are used for which channels. In principle, only two kinds of...

Info Pnt Signaling Systems 2

Tue, 10 Jan 2012 19:33:45 GMT

1. These two phases take place only if an endpoint needs to register with its GK. 2. This phase takes place for every call except when no GK is present. 3. Since the call signaling channel may not need to stay up for the whole duration of the connection, the Q.931 termination sequence may happen earlier in the call, although obviously after call setup. The decision is made by the GK. 1. These two phases take place only if an endpoint needs to register with its GK. 2. This phase takes place for...

Advanced Topology Discovery MeshNetworks

Tue, 10 Jan 2012 18:31:24 GMT

The most fundamental element of any network management is the ability to visualize the location and interconnectivity of nodes as well as the utilization of network resources in this case wireless channels at each location. This is especially important for larger scale WMN as they need to coexist with, rather than compete with, other residential and office wireless LANs. The three research questions here are the following. First, how to utilize multiple radios and potentially smart antennas...

Coding VoiceChannels

Tue, 10 Jan 2012 15:39:10 GMT

Older PCM systems used a 7-bit code, and modern systems use an 8-bit code with its improved quantizing distortion performance. The companding and coding are carried out together, simultaneously. The compression and later expansion functions are logarithmic. A pseudologarithmic curve made up of linear segments imparts finer granularity to low-level signals and less granularity to the higher-level signals. The logarithmic curve follows one of two laws, the A-law and the -law pronounced mu-law ....

Messages for Mobility Management MM Signaling Systems 2

Tue, 10 Jan 2012 13:46:37 GMT

Authentication Request. This message is sent by the network on SDCCH to check the authenticity of the MS. It includes the random number IE RAND . Authentication Response. This message is sent by a MS on SDCCH in response to the Authentication Request. It includes the signed response SRES . CM Service Request. This message is sent by a MS on SDCCH to request a connection management CM service. It includes the CM service type IE, which specifies the requested service e.g., the setup of a...

Policy Control Signaling MultimediaTelephony

Tue, 10 Jan 2012 07:07:02 GMT

Policy control is an important mechanism for a Multimedia Telephony service since it is the mechanism that is used to coordinate events such as Multimedia Telephony session initiation modification in the application layer and resource management events such as bearer establishment modification in the IP bearer layer. Policy control is the mechanism that enables IMS to enforce suitable QoS for a given service or media flow. In 3GPP release 6, two different architectures were used for policy...

Tcuabort Signaling Systems 2

Tue, 10 Jan 2012 05:19:19 GMT

Figure 16.1-4. Transaction examples. Figure 16.1-4. Transaction examples. case b , the invoked operation yields information, which is returned in an End message with a RR-L component. In case c , ASE-2 needs more information from ASE-1 before it can execute Invoke 1. It therefore returns a Continue message, whose Invoke 2 requests the information. After executing Invoke 2, ASE-1 sends a Continue message, in which RR-L 1 contains the requested information. ASE-2 now executes Invoke 1 and returns...

GPRS Rei5 Architecture Wireless Networks 2

Tue, 10 Jan 2012 02:07:31 GMT

As shown in Figure 10.2, the GPRS mobile system consists of three main entities Mobile Station MS , Radio Access Network RAN , and Core Network CN . A mobile station refers to the mobile equipment on which a user executes mobile services and applications i.e., voice services, SMS . A mobile station communicates with the base station that controls the radio channel within its coverage area or a cell, so to speak . Multiple base station systems interconnect and form the network called RAN. RAN is...