Changes between Version 6 and Version 7 of ConceptandMotivation

Timestamp:

07/02/10 21:07:20 (16 years ago)

Author:

vuk (IP: 147.83.105.169)

Comment:

--

ConceptandMotivation

@@ -1 +1 @@
 === Concept ===
-
-The ALOE concept tries to address the main issues related with the Software Radio technology. It assumes the need of supporting, partial or total, reconfiguration of the radio processing chain, the need to deploy the radio application onto a heterogeneous hardware platform capable to assume the high computing requirements of modern wireless systems, the need to assure strong real-time execution constraints, the need to easily develop and integrate software modules and the possibility to execute them in different types of processors assuming an easy portability.
 
 [[Image(ALOEV0.png, 400px, align=right)]]
 
-One of the most relevant objectives in the process of defining a common framework to develop and deploy software radio applications is to eliminate platform (hardware and support software) dependencies. On the other hand, radio applications are built through a set of software modules (hardware or software based) that communicates among them. The common used terms denominates such modules as “objects”. Therefore each one of such objects are signal processing blocks, some of them with important requirements in terms of computing resources, that needs to acquire/deliver information from/to other objects through proper interfaces. Nevertheless, one of the most relevant assumptions of PHAL-OE is that such interfaces between objects are unknown at object development time. Only at execution time all the required objects will be integrated and the entire radio application will be built.
+The software-defined radio (SDR) concept envisages dynamic waveform reconfigurations. This, however, requires software and hardware support and computing resource management, in particular. The abstraction layer and operating environment (ALOE) is an open-source SDR framework with cognitive computing resource management capabilities. It supports partial or total reconfigurations of the transceiver digital signal processing chain (waveform) while facilitating the deployment of waveforms on heterogeneous and distributed hardware resources. The main attributes and functionalities of ALOE are:
 
-All these objectives have pushed us to define and develop a multi-platform software abstraction layer and execution environment, ALOE (Abstraction Layer & Operating Environment), capable to provide such features. The list of the main functionalities where the PHAL-OE must provide support on includes:
+   *    Flexibility – be able to trade implementation efficiency against flexibility. An efficient implementation makes best use of the available computing resources (low resource overhead), whereas a flexible solution allows for dynamic reconfigurations at the cost of some resource overhead.
 
-•       Flexibility. The framework must efficiently implement the flexibility concept required by SDR. It is assumed to be based in the capacity to facilitate the reconfiguration as the basic mechanism providing flexibility. 
+   *    Execution control – coordinate execution across the entire distributed computing system.
 
-•       Execution control management. The coordinated execution of the whole system must be assured.
+   *    Abstractions – hide platform details and heterogeneity from radio applications, enabling portability.
 
-•       Hide the platform heterogeneity to the radio application. Abstraction layers are required are basic mechanisms to provide such feature.
- 
+   *    Data packet oriented messaging – packet-oriented instead of processor or device-specific communication mechanisms.
 
-•       Computing resource management. Under a scenario with limited computing resources the need of a specific mechanism to manage the available resources promotes the efficiency in the whole system and extends its interactions with the radio resources management part. In addition it is capable to assure the overcoming of the real-time constraints.
+   *    Parameter control – runtime signal (parameter or variable) management.
 
-•       Data packet oriented messaging. Not processor (device) oriented communication mechanisms. Data packet oriented communication network among the heterogeneous processors is built.
+   *    Resource monitoring – computing system/environment awareness.
 
-•       Parameter or variable (signals) evolution capture during the execution of the application. 
-
-•       Processing resource parameters evolution captured for autonomous management or control.
-
-•       Auto-learning/cognitive capabilities for the internal resource management can be easily incorporated. 
-
-•       Support to the Cognitive Radio strategies thanks to the capacity to capture, in a coordinated way, relevant information from different layers of the radio and computing system.
+   *    Computing resource management – efficiently manage the distributed and limited computing resources.
 
 
 === Layers ===
 
-Previous figure tries to illustrate the PHAL-OE concept. On the bottom we can see the Hardware Layer where we can found several processors or Processing Elements (PE) physically interconnected among them. On top of the figure we can see the Abstract Application Layer where a graph of a radio application tries to define the required tasks (objects) and the data flow among them. In the Real Application Layer we can see the previous tasks but using the services or functionalities provided by PHAL-OE to build coherently the radio application. On th PHAL-OE Layer we observe that from the point of view of the tasks (objects) conforming the radio application all them only see the same platform, the PHAL-OE Platform, not being aware of any detail related with the hardware. On such layer, but from the hardware point of view, we can find the specific implementation of the PHAL-OE functions for each one of the processors used to build the entire Hardware Layer.
+While defining a common framework for developing and deploying SDR applications it is important to eliminate any platform (hardware and supporting software) dependency. Radio applications are built through a set of precedence-constrained modules. (These modules may also be called “objects”.) Each module represents a more or less complex signal processing block that acquires information from preceding objects in the processing chain and delivers the processed information to the following modules. ALOE assumes that object interfaces are unknown at design time. This enables dynamically composing and recomposing processing chains at execution time while integrating the objects that assemble the desired waveform.
 
+The figure shows the ALOE layers. The hardware layer typically consists of several processors or processing elements (PEs), which are physically interconnected. The ALOE Layer abstracts the hardware platform, providing a homogeneous execution environment, the ALOE platform, to applications. The abstract application layer models a radio application or waveform by means of the task graph. It abstracts the waveform modules, providing information about the involved tasks (modules or objects), their precedence constraints and data flow requirements. The real application layer uses the services or functionalities provided by the ALOE layer for assembling the complete waveform and distributing its modules among the available hardware resources.
 
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