| 1. |
- Angelin, Lars, et al.
(författare)
-
A Congestion Control Mechanism for Signaling Networks based on Network Delays
- 1995
-
Konferensbidrag (refereegranskat)abstract
- Congestion control in Signaling System #7 faces new challenges as mo-bile communication systems and Intelligent Networks grow rapidly. New ser-vices change traffic patterns, add to signalling network load, and raise demands on shorter service completion times. To handle new demands, the congestion control mechanisms must foresee an overload situation, and respond to it so that the network can maintain high probability for successful service comple-tion. With the introduction of a state machine and a memory function for each signaling link it is possible to predict the completion time of a service session and to detect an emerging congestion. If the predicted completion time of a service session is too long, the session is annihilated. This is the foundation of a congestion control mechanism that reacts fast on information supplied by the congested part of the network. The congestion control mechanism increases the ratio of successfully completed service sessions during congestion by several hundred percent.
|
|
| 2. |
- Angelin, Lars, et al.
(författare)
-
A Network Approach to Signalling Network Congestion Control
- 1995
-
Konferensbidrag (refereegranskat)abstract
- Congestion control in Signaling System #7 faces new challenges as mobile communication systems and Intelligent Networks grow rapidly. New services change traffic patterns, add to signalling network load, and raise demands on shorter service completion times. To handle new demands, the congestion control mechanisms must foresee an overload situation, and respond to it so that the net-work can maintain high probability for successful service completion. By measur-ing the time consumption for the initial Message Signalling Units of a service session it is possible to predict the duration of the service session and to detect an emerging congestion. If the predicted duration of the service session is too long, the service session is annihilated. This is the foundation of a congestion control mechanism that reacts fast and on information supplied by the congested part of the network. The congestion control mechanism increases the ratio of successfully completed services during congestion by several hundred percent.
|
|
| 3. |
- Arvidsson, Åke, et al.
(författare)
-
Congestion Control in Intelligent Networks for Real Time Performance and Profit Optimisation
- 1996
-
Konferensbidrag (refereegranskat)abstract
- Current developments in technologies and markets stress the importance of exible and robust performance optimisation and congestion control. In intelligent networks, congestion control has traditionally taken a purely technical view and focused on pro- tecting individual nodes from harmful overloads. We take a profit oriented, network wide view and develop a congestion control mechanism to ensure real time performance under profit maximisation. Numerical studies in a simulator show that the proposed mechanism is robust and, in particular in overloaded states, provides a substantial improvement in comparison to conventional load control mechanisms.
|
|
| 4. |
- Arvidsson, Åke, et al.
(författare)
-
Profit Optimal Congestion Control in Intelligent Networks
- 1997
-
Ingår i: 15th International Teletraffic Congress on Teletraffic Contributions for the Information. - WASHINGTON, DC : ELSEVIER SCIENCE PUBL B V. - 0444825983 ; , s. 911-920
-
Bokkapitel (refereegranskat)abstract
- Current developments in technologies and markets stress the importance of exible and robust performance optimisation and congestion control. In intelligent networks, conges- tion control has traditionally taken a mainly technical view and focused on protecting individual nodes from harmful overloads. We take a profit oriented, network wide view and develop a congestion control mechanism to ensure profit maximisation under real time performance. Numerical studies in a simulator show that the proposed mechanism is robust and, in particular in overloaded states, provides a substantial improvement in comparison to conventional load control mechanisms.
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
- Berg, Miguel, et al.
(författare)
-
A Radio Resource Management Concept for "Bunched" Personal Communication Systems
- 1997
-
Konferensbidrag (refereegranskat)abstract
- The radio resource management (RRM) techniques used in current 2nd generation mobile communication systems rely heavily on fixed frequency or timeslot allocation techniques which are not well suited for large variations in data rates. Spread spectrum systems proposed provide partial solutions to this problem but exhibit deficiencies when faced with uneven user populations. The overall objective of ACTS project AC090 FRAMES is to define, develop and evaluate a wideband multiple radio access scheme fulfilling the UMTS requirements. Within the project several RRM concepts have been proposed. The "bunch" concept discussed in this paper uses synchronous dynamic physical layer radio resource reservation combined with fast SIR based power control in a local cluster ("bunch"). Uncontrolled, "inter bunch", interference is handled by time/frequency hopping ("interference averaging"). In the paper some initial performance results are presented.
|
|
| 8. |
|
|
| 9. |
- Jarlman, O, et al.
(författare)
-
Laser transillumination of breast tissue phantoms using time-resolved techniques
- 1996
-
Ingår i: European Radiology. - 0938-7994. ; 6:3, s. 387-392
-
Tidskriftsartikel (refereegranskat)abstract
- The objective of this study was to evaluate a pulsed laser transillumination technique based on time-resolved detection on breast-tissue-like phantoms. Experiments have been performed on tissue-like plastic phantoms with different scattering characteristics. The effects of time-gate width, size, localisation and refractive index of hidden objects have been scrutinised. Our study showed that the shorter the time-gate the higher the contrast. The contrast is very dependent of the size of the hole, whereas the full width half maximum is not. Furthermore, the investigation showed that the changes of early detected light in an experimental setting is due to scattering, adn not to a higher speed of the transmitted light.
|
|
| 10. |
- Jarlman, O, et al.
(författare)
-
Time-resolved white light transillumination for optical imaging
- 1997
-
Ingår i: Acta Radiologica. - : SAGE Publications. - 1600-0455 .- 0284-1851. ; 38:1, s. 185-189
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: To describe a new breast-imaging method with the potential of multi-spectral optical transillumination based on a time-resolved technique. Material and Methods: A breast phantom was irradiated with ultra-short laser pulses of white light generated by self-phase modulation of an incident high-power laser pulse in water. Time-resolved detection of the transmitted light was performed. Contrast resolution was studied using different absorbers located inside the breast phantom. Results and Conclusion: The results showed that simultaneous, multi-spectral transillumination is possible. The technique can also be used for measurements of optical properties in tissue.
|
|
