Network

Term Project

Introduction

Brief overview of the firm

San Francisco-based DD Communications (an alias) is a wireless telecommunication company that delivers only data. The company provides market-leading connectivity solutions for monitoring, tracking, messaging, and mobile telemetry services through existing wireless infrastructures.[1]

DD Communications has patented embedded software that is able to deliver data across wireless networks. This venture company doesn’t own any of its own wireless infrastructure, instead, it has contracts with many wireless service providers like Verizon, AT & T, etc., so it uses various carriers’ networks and pays them monthly based on where and how much it uses.

Current business issues

The business objective of DD Communications is to deliver data in real time without losing information. Data delivery is harder than voice delivery in terms of the system tolerance level. When you talk with someone over a cellular-phone, if you miss one word in a sentence, you can still understand the overall meaning or you can ask for clarification. However, in data delivery, if you miss some bits in data sets, they can be very critical, because it may include very important sections of data and it may be impossible to recover the entire data set without those bits. In addition, it’s not always clear that data is missing until further in the process. Therefore, data delivery networks have to run 24 hours 7 days a week without any interruption.

Statement and discussion of the problem(s) under study

To support their business objective, DD Communications has networks for data delivery that are both internally stable and protected from attacks. This is their system diagram.

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Note: HLR (Home Location Register), STP (Signaling Transfer Point), PSTN (Public Switched Telephone Network), SS7 (Signaling System No. 7 – ANSI Standard)

As shown in the diagram, the most important parts are HLRs and STPs, because...