Wednesday, August 31, 2022

Ruminating on TMForum

The TM Forum (TMF) is an organisation of over 850 telecom firms working together to drive digital innovation. They created a standard known as TMF Open APIs, which provides a standard interface for the interchange of various telco data.

TM Forum’s Open APIs are JSON-based and follow the REST paradigm. They also share a common data model for Telecom.

Any CSP (Communications service provider) can accelerate their API journey by leveraging the TMForum API contracts. The link below gives some of the examples of the API standards available:

Currently, there are around 60+ APIs defined in the Open API table of TMForum. 

Few examples of the APIs are as follows:

  • Customer Bill Management API: This API allows operations to find and retrieve one or several customer bills (also called invoices) produced for a customer.
  • Customer Management API: Provides a standardized mechanism for customer and customer account management, such as creation, update, retrieval, deletion and notification of events.
  • Digital Identity Management API: Provides the ability to manage a digital identity. This digital identity allows identification of an individual, a resource, or a party Role (a specific role - or set of roles - for a given individual).
  • Account Management API: Provides standardized mechanism for the management of billing and settlement accounts, as well as for financial accounting (account receivable) either in B2B or B2B2C contexts.
  • Geographic Address Management API: Provides a standardized client interface to an Address management system. It allows looking for worldwide addresses
  • Geographic Site Management API: Covers the operations to manage (create, read, delete) sites that can be associated with a customer, account, service delivery or other entities.
  • Payment Management API: The Payments API provides the standardized client interface to Payment Systems for notifying about performed payments or refunds.
  • Payment Method Management API: This API supports the frequently-used payment methods for the customer to choose and pay the usage, including voucher card, coupon, and money transfer.
  • Product Ordering Management API: Provides a standardized mechanism for placing a product order with all the necessary order parameters.
  • Promotion Management API: Used to provide the additional discount, voucher, bonus or gift to the customer who meets the pre-defined criteria.
  • Recommendation Management API: Recommendation API is used to recommend offering quickly based on the history and real-time context of a customer.
  • Resource Function Activation Management API: This API introduces Resource Function which is used to represent a Network Service as well as a Network Function.

The GitHub repository of TMForum is a great place to get acquainted with the APIs -

Since the TMForum defines the data model in JSON format, any noSQL datastore that stores data as JSON documents becomes an easy option to quickly implement an API strategy. For example, TMF data model of the API can be persisted 1:1 in Mongo database without the need for additional mappings as shown here -

Monday, August 29, 2022

mAP (mean Average Precision) and IoU (Intersection over Union) for Object Detection

mAP (mean Average Precision) is a common metric used for evaluating the accuracy of object detection models. The mAP computes a score by comparing the ground-truth bounding box to the detected box. The higher the score, the more precise the model's detections.

The following articles give a good overview of the concepts of precision, recall, mAP, etc.

Some snippets from the above article:

"When a model has high recall but low precision, then the model classifies most of the positive samples correctly but it has many false positives (i.e. classifies many Negative samples as Positive). When a model has high precision but low recall, then the model is accurate when it classifies a sample as Positive but it may classify only some of the positive sample.

Higher the precision, the more confident the model is when it classifies a sample as Positive. The higher the recall, the more positive samples the model correctly classified as Positive.

As the recall increases, the precision decreases. The reason is that when the number of positive samples increases (high recall), the accuracy of classifying each sample correctly decreases (low precision). This is expected, as the model is more likely to fail when there are many samples.

The precision-recall curve makes it easy to decide the point where both the precision and recall are high. The f1 metric measures the balance between precision and recall. When the value of f1 is high, this means both the precision and recall are high. A lower f1 score means a greater imbalance between precision and recall.

The average precision (AP) is a way to summarize the precision-recall curve into a single value representing the average of all precisions. The AP is the weighted sum of precisions at each threshold where the weight is the increase in recall. 

The IoU is calculated by dividing the area of intersection between the 2 boxes by the area of their union. The higher the IoU, the better the prediction.

The mAP is calculated by finding Average Precision(AP) for each class and then average over a number of classes."

Thursday, August 25, 2022

Ruminating on Bloom's Taxonomy

I was trying to help my kids understand the importance of deeply understanding a concept, instead of just remembering facts. 

I found the knowledge pyramid of Bloom an excellent illustration to help my kids understand how to build skills and knowledge. The following article on Vanderbilt University site is a good read to understand the concepts -

Thursday, August 11, 2022

Handling Distributed Transactions in a microservices environment

 In a distributed microservices environment, we do not have complex 2-phase commit transaction managers. 

We need a simpler approach and we have design patterns to address this issue. A good article explaining this strategy is available here -

The crux of the idea is to issue compensating transactions whenever there is a failure in one step of the flow. A good sample usecase for a banking scenario (with source code) is available here -

Wednesday, August 10, 2022

API contract first design

 I have always been a great fan of the 'Contract-First' API design paradigm. The Swagger (OpenAPI) toolset makes it very simple to design new API contracts and object schemas. 

There is a Swagger Pet Store demo available here, wherein we can design API contracts using a simple YAML file: 

After the API contract has been designed and reviewed, we can quickly generate stubs and client code in 20 languages using Swagger Codegen