Embedded Software: Powering IoT-Connected Devices from Cars to Industrial Robots

Embedded software is the invisible driver behind devices you wouldn’t normally call “computers”— car systems, industrial robots, telecom gear, medical monitors, smart meters, and more. Unlike general-purpose software that runs on laptops or phones, embedded software is built to operate inside specific hardware, under tight constraints, and often with real‑time deadlines. Increasingly, these devices are also connected, forming the Internet of Things (IoT). That connectivity brings huge opportunities—remote updates, predictive maintenance, data-driven optimization—but also raises new challenges for reliability, safety, and security.

This article breaks down the core problem embedded teams face as they join the IoT, the common methods to solve it, and a practical “best solution” blueprint that balances performance, cost, security, and maintainability. Already, there are many reports of such devices getting hacked or other problems that cause concern among consumers.

Problem:

How do we reliably control physical devices—cars, industrial robots, telecom switches, and similar systems—under strict real‑time, safety, and power constraints, while also connecting them to networks and the cloud for monitoring, analytics, and updates?

At first glance, “just add Wi‑Fi” sounds simple. In practice, the problem is multidimensional:

• Real-time behavior: A robotic arm must execute a 1 kHz control loop without jitter. A car’s airbag controller must respond in milliseconds. Delays or missed deadlines can cause damage or harm.
• Reliability and safety: Devices must continue operating under faults (e.g., sensor failure, memory errors) and fail safely if they cannot.
• Security: Networked devices are attack surfaces. We need secure boot, encrypted comms, authenticated updates, and protection for keys and secrets.
• Resource constraints: Many devices use microcontrollers with limited RAM/flash, modest CPU, and tight power budgets—especially on batteries or energy harvesting.
• Heterogeneity: The device landscape mixes microcontrollers (MCUs), microprocessors (MPUs), FPGAs, and specialized chips. Protocols vary: CAN in cars, EtherCAT in robots, Modbus in factories, cellular in the field.
• Lifecycle and scale: Devices must be buildable, testable, deployable, and updatable for 5–15 years, often across large fleets with different hardware revisions.
• Compliance and certification: Domains like automotive (ISO 26262), industrial (IEC 61508), and medical (IEC 62304) impose strong process and design requirements.

Consider a simple example: a connected industrial pump. Without careful design, a cloud update could introduce latency in the control loop, risking cavitation and equipment damage. Or a missing security check could allow a remote attacker to change pressure settings. The problem is balancing precise local control with safe, secure connectivity and long-term maintainability.

Possible methods:

There are many valid paths to build embedded, IoT-connected systems. The right mix depends on your device’s requirements. Below are common approaches and trade-offs.

1) Pick the right compute platform

• Microcontroller (MCU): Low power, deterministic, cost-effective. Ideal for tight real‑time tasks, sensors, motor control. Typical languages: C/C++. Often paired with an RTOS (FreeRTOS, Zephyr) or even bare‑metal for maximum determinism.
• Microprocessor (MPU) + Embedded Linux: More memory/CPU, MMU, threads/processes, richer networking and filesystems. Great for gateways, HMIs, and complex stacks. Common distros: Yocto-based Linux, Debian variants, Buildroot.
• Heterogeneous split: MCU handles time-critical loops; MPU runs higher-level coordination, UI, and cloud connectivity. Communicate via SPI/UART/Ethernet, with well-defined interfaces.

2) Bare‑metal, RTOS, or Embedded Linux?

• Bare‑metal: Max control and minimal overhead. Good for ultra-constrained MCUs and very tight loops. Harder to scale features like networking.
• RTOS (e.g., FreeRTOS, Zephyr, ThreadX): Deterministic scheduling, tasks, queues, timers, and device drivers. A common middle ground for IoT devices.
• Embedded Linux: Full OS services, process isolation, rich protocol stacks, containers (on capable hardware). Best when you need advanced networking and storage.

3) Connectivity protocols and buses

• Local buses: CAN/CAN FD (automotive), EtherCAT/Profinet (industrial motion), I2C/SPI (sensors), RS‑485/Modbus (legacy industrial).
• Network layers: Ethernet, Wi‑Fi, BLE, Thread/Zigbee, LoRaWAN, NB‑IoT/LTE‑M/5G depending on range, bandwidth, and power.
• IoT app protocols: MQTT (pub/sub, lightweight), CoAP (UDP, constrained), HTTP/REST (ubiquitous), LwM2M (device management).

Example: A factory robot might use EtherCAT for precise servo control and Ethernet with MQTT over TLS to send telemetry to a plant server, with no direct cloud exposure.

4) Security from the start

• Root of trust: Use a secure element/TPM or MCU trust zone to store keys and enable secure boot.
• Secure boot and firmware signing: Only run images signed by your private key. Protect the boot chain.
• Encrypted comms: TLS/DTLS with modern ciphers. Validate server certs; consider mutual TLS for strong identity.
• Least privilege: Limit access between components. On Linux, use process isolation, seccomp, and read‑only root filesystems.
• SBOM and vulnerability management: Track all third‑party components and monitor for CVEs. Plan patch pathways.

5) OTA updates and fleet management

• A/B partitioning or dual-bank firmware: Updates are written to an inactive slot; roll back if health checks fail.
• Delta updates: Reduce bandwidth and time by sending only changed blocks.
• Device identity and groups: Track versions, hardware revisions, and cohorts. Roll out to canary groups first.
• Remote configuration: Keep device config separate from code; update safely with validation.

6) Data handling and edge computing

• Buffering and QoS: When offline, queue telemetry locally. Use backoff and retry strategies.
• Local analytics: Preprocess or compress sensor streams; run thresholding or simple ML at the edge to save bandwidth and improve response time.
• Time-series structure: Tag data with timestamps and units; standardize schemas to simplify cloud ingestion.

7) Safety and reliability patterns

• Watchdogs and health checks: Reset hung tasks; monitor control loop timing and sensor sanity.
• Fail‑safe states: Define and test safe fallbacks (e.g., robot brakes on comms loss).
• Memory protection: Use MMU/MPU or Rust for memory safety; consider ECC RAM for critical systems.
• Diagnostics: Fault codes, self-tests at boot, and clear service indicators.

8) Languages and toolchains

• C/C++: Ubiquitous for MCUs and performance. Apply MISRA or CERT rulesets; use static analysis.
• Rust: Memory safety without GC; growing ecosystem for embedded and RTOS integration.
• Model‑based development: Tools that generate code for control systems (common in automotive/robotics).
• Python/MicroPython: Useful for rapid prototyping on capable MCUs/MPUs; not ideal for hard real‑time.

9) Testing and validation

• Unit and integration tests: Cover drivers, protocols, and control logic. Mock hardware where possible.
• HIL/SIL: Hardware‑in‑the‑Loop and Software‑in‑the‑Loop simulate sensors/actuators to test edge cases.
• Continuous integration: Build, run static analysis, and flash test boards automatically.
• Fuzzing and fault injection: Stress parsers and protocols; simulate power loss during updates.

10) User interaction and UI

• Headless devices: Provide a secure local service port or Bluetooth setup flow.
• HMI panels: Use frameworks like Qt or LVGL for responsive, low-latency interfaces.

11) Interoperability in the field

• Industrial: OPC UA for structured data exchange; DDS or ROS 2 for robotics communication.
• Automotive: AUTOSAR Classic/Adaptive for standardized ECU software architectures.
• Telecom: NETCONF/YANG for network device configuration, SNMP for legacy monitoring.

Each method offers a piece of the puzzle. The art is combining them into a cohesive, maintainable architecture that meets your device’s real‑time and safety needs while enabling safe connectivity.

Best solution:

Below is a practical blueprint you can adapt to most IoT-connected embedded projects, from EV chargers to robotic workcells.

1) Start with crisp requirements

• Real‑time class: Identify hard vs. soft real‑time loops and their deadlines (e.g., 1 kHz servo loop, 10 ms sensor fusion, 1 s telemetry).
• Safety profile: Define hazards, fail‑safe states, and required standards (ISO 26262, IEC 61508, etc.).
• Connectivity plan: Who needs access? Local network only, or cloud? Bandwidth and offline operation expectations?
• Power and cost budget: Battery life, energy modes, BOM ceiling.
• Lifecycle: Expected service life, update cadence, and fleet size.

2) Use a split architecture for control and connectivity

Separate time‑critical control from connected services:

• Control MCU: Runs bare‑metal or RTOS. Owns sensors/actuators and critical loops. No direct Internet exposure.
• Application/Connectivity MPU (or smart gateway MCU): Runs Embedded Linux or an RTOS with richer stacks. Handles device management, OTA, data buffering, UI, and cloud comms.

Connect the two via a simple, versioned protocol over SPI/UART/Ethernet. Keep messages small and deterministic. Example messages: “set speed,” “read status,” and “fault report.” This decoupling preserves tight control timing while enabling safe updates and features.

3) Layer your software and enforce boundaries

• Hardware Abstraction Layer (HAL): Encapsulate registers and peripherals to isolate hardware changes.
• Drivers and services: SPI/I2C, storage, logging, crypto, comms.
• RTOS or OS layer: Tasks/threads, scheduling, queues, interrupts.
• Application layer: Control logic, state machines, and domain rules.
• IPC/message bus: Use queues or pub/sub internally to decouple components.

On Linux, use processes with least privilege, read-only roots, and minimal setcap. On MCUs, leverage an MPU for memory isolation if available.

4) Build security in, not on

• Secure boot chain: ROM bootloader → signed bootloader → signed firmware. Store keys in a secure element when possible.
• Mutual TLS for cloud: Each device has a unique identity (X.509 cert); rotate keys when needed.
• Principle of least privilege: Limit which component can update what. Protect debug interfaces; disable in production or require auth.
• Threat modeling: Enumerate attack paths: network, physical ports, supply chain, OTA. Plan mitigations early.

5) Make OTA safe and boring

• A/B partitions with health checks: Boot new image only if watchdog and self-tests pass. Roll back otherwise.
• Signed updates and versioning: Reject unsigned or downgraded images unless explicitly allowed for recovery.
• Staged rollouts and canaries: Update a small subset first; monitor metrics; then expand.
• Config as data: Keep settings out of firmware images to avoid risky reflashes for small changes.

6) Design for observability

• Structured logs and metrics: Timestamped, leveled logs; key metrics like loop jitter, queue depths, temperature, battery.
• Device health model: Define states (OK, Degraded, Fault) and expose them via local APIs and remote telemetry.
• Unique device IDs and inventory: Track hardware revisions, sensor calibrations, and component versions.

7) Test like production depends on it (because it does)

• CI pipeline: Build for all targets, run static analysis (MISRA/CERT checks), and unit tests on every commit.
• HIL rigs: Automate flashing, power cycling, and sensor simulation. Inject faults like packet loss or brownouts.
• Coverage and trace: Use trace tools to verify timing; collect coverage metrics for critical modules.

8) Choose fit-for-purpose tools and languages

• C/C++ with guardrails: Adopt coding standards, code reviews, sanitizers (on host), and static analysis.
• Rust where feasible: For new modules, especially parsing and protocol code, Rust can reduce memory safety bugs.
• Model-based where it shines: For control loops, auto-generated C from validated models can be robust and testable.

9) Energy and performance tuning

• Measure first: Use power profiling tools; identify hot spots.
• Use low-power modes: Sleep between events; batch transmissions; debounce interrupts.
• Right-size buffers and stacks: Avoid over-allocation on constrained MCUs; use compile-time checks.

10) Interoperability plan

• Industrial robots: Use EtherCAT for deterministic motion; OPC UA for supervisory data; ROS 2 for higher-level coordination where appropriate.
• Automotive ECUs: Stick to AUTOSAR patterns; bridge to Ethernet for higher bandwidth domains.
• Telecom equipment: NETCONF/YANG for config; streaming telemetry for real-time monitoring.

Example blueprint in action: a connected industrial robot cell

Suppose you’re integrating a six-axis robot on a production line:

• Control MCUs: Each servo drive runs a 1 kHz control loop on an MCU with an RTOS. They communicate over EtherCAT to a motion controller.
• Cell controller: An embedded Linux box orchestrates tasks, provides an HMI, logs data, and exposes a local API over Ethernet.
• Connectivity: The cell controller publishes telemetry (temperatures, currents, cycle times) to a plant server via MQTT/TLS. No direct cloud access; the plant server handles aggregation and forwards selected data to the cloud.
• Security: Secure boot on all controllers; device certificates provisioned at manufacturing; TLS everywhere; physical debug ports disabled or locked.
• OTA: A/B updates for the cell controller; a controlled update channel for servo firmware with staged rollout during maintenance windows.
• Safety: On loss of EtherCAT sync or comms fault, drives engage brakes and enter a safe-stop state. Watchdogs monitor loop jitter and temperature thresholds.
• Observability: Metrics include loop timing, bus latency, and fault counters; alerts trigger maintenance before failures.

This pattern isolates the safety-critical motion control from broader connectivity while still enabling efficient monitoring and updates.

Pitfalls to avoid

• Coupling cloud logic to control loops: Never tie real-time control to remote services.
• Underestimating OTA complexity: Without rollback and health checks, you risk bricking devices.
• Weak identity management: Shared secrets across a fleet are a single point of failure.
• Skipping threat modeling: It’s cheaper to design security than to retrofit after an incident.
• Ignoring long-term maintenance: Track dependencies and plan updates for the lifetime of the device.

How this scales across domains

The same blueprint adapts well:

• Automotive: Separate safety ECUs (airbag, ABS) from infotainment and telematics. Use gateways to strictly control inter-domain messages. Over-the-air updates are staged and signed, with robust rollback.
• Telecom: Control planes remain isolated; data planes are optimized for throughput; management planes expose standardized interfaces for orchestration and automated updates.
• Smart energy: Meters perform local measurement and tamper detection; gateways handle aggregation and cloud messaging over cellular with tight key management.

Why this is the “best” solution in practice

There’s no one-size-fits-all design, but this approach is best for most teams because it:

• Preserves determinism: Real-time control is insulated from network variability and software bloat.
• Improves security: Clear trust boundaries, secure boot, and strong identity reduce attack surfaces.
• Simplifies updates: A/B and staged rollouts reduce risk and operational headaches.
• Eases compliance: Layered architecture and traceable processes align with safety standards.
• Scales to fleets: Built-in observability and device management enable efficient operations.

Quick glossary

• Embedded software: Software running on dedicated hardware to perform specific functions.
• IoT (Internet of Things): Network of connected devices that collect and exchange data.
• RTOS: Real-Time Operating System for deterministic task scheduling.
• OTA: Over‑the‑Air update mechanism for remote firmware and software updates.
• Root of trust: Hardware/software foundation that ensures system integrity from boot.

Closing thought

Embedded software used to be about getting the control loop right and shipping reliable hardware. Today, it’s about doing that and connecting devices safely to the wider world. With a split architecture, security baked in, disciplined testing, and robust OTA, you can power everything from cars to industrial robots—and keep them secure, up to date, and performing for years.

By treating connectivity as an extension of reliable control—not a replacement for it—you get the best of both worlds: precise, safe devices that also deliver the data, updates, and insights modern operations demand.

Key takeaways:

• Isolate real-time control from connected services.
• Design security and OTA from day one.
• Invest in testing, observability, and standards compliance.
• Use the right protocols and tools for your constraints and domain.

With these principles, embedded software becomes the engine that safely powers IoT-connected devices—on the road, on the line, and across the network.

What is WiMax technology?

Worldwide inter-operability for microwave access or wimax is standard developed for wireless communications that has been designed so as to deliver data rates of 30-40 mbps. The update in the technology in the year 2011 upgraded the technology to provide around 1 gbps for the stations that were fixed. 

- The Wimax forum is responsible for naming the technology as Wimax. 

- This forum was formed in the year of 2001 for the promotion of the inter-operability and conformity of this standard. 

- The Wimax has been defined by the forum as the technology based up on standards that enable the last mile wireless broadband delivery as alternative for the DSL and the cable thing. 

- The IEEE 802/ 16’s interoperability implementations are referred to as the WiMax. 

- The wimax forum has ratified this family of standards. 

- By virtue of the certification provided by this forum, the vendors are able to sell mobile and fixed products that are wimax certified. 

- This is done for ensuring that a level of inter-operability is maintained at par with the other products that have been also certified for the same profile. 

- The ‘fixed wimax’ is the name given to the original IEEE 802.16 standards.

- ‘Wifi on steroids’ is the term used to refer to WiMax sometimes. 

It has got a number of applications such as in:

Ø  Broadband connections

Ø  Cellular back-haul

Ø  Hot spots and so on.

- This technology shares some similarity with the Wifi technology however, this one is more capable of transmitting data at greater distances.

It is because of its range and bandwidth that the WiMax is suitable for the following applications:

Ø  Provides services such as the IPTV services and VoIP (telecommunications services).

Ø  Provides mobile broadband connectivity that is portable across the cities and countries and that can be accessed via different kinds of devices.

Ø  Provides an alternative for DSL and cable in the form of wireless last mile broadband access.

Ø  Acts as a source of internet connectivity.

Ø  Metering and smart grids.

- This technology can be used at home for providing internet access across the countries. 

- This has also caused a rise in the market competition. 

- The WiMax is even economically feasible. 

- Mobile wimax has been used as a replacement for the technologies like CDMA, GSM that are cellular phone technologies.  

- The technology has also been used as an overlay for increasing the capacity.  

- The fixed wimax is now used for 2g, 3g and 4g networks as a wireless back-haul technology in almost all the nations whether they are developed or developing.  

- In some states of North America, this technology is provided through a numbered of copper wire line connections. 

- On the other hand, the technology is back hauled via satellites in case of the remote cellular operations.  

- While in other cases even microwave Links are used. 

- The bandwidth requirements of the WiMAX demand more substantial back-haul when compared to other legacy cellular applications. 

- In some of the cases, the sites have been aggregated by the operators by use of Wireless Technology.  

- The traffic is then introduced to the fiber networks as per the convenience.  

- The technologies that provide triple play services are directed compatible with the WiMAX.  

- These services might include multi-casting and quality of service. 

- WiMax has been widely used for providing assistance in the communications. 

- The Intel Corporation has donated the hardware for WiMax technology for assisting the FCC (federal communications commission) and FEMA etc.

- The subscribers’ stations or SS are the devices which are used for connecting to a WiMAX Network. 

- These devices might be portable such as the following:

      > Handsets and smart phones

      > PC peripheral such as USB dongles, PC Cards and so on. 

      > Embedded devices in notebooks.

What are advantages and limitations of Wi-Fi?

The Wi-Fi has its own set of advantages and limitations. 

Advantages of WiFi

- WiFi makes the deployment of local Area Networks or LANs quite cheap.  

- There are some areas where the cables cannot be installed such as in historical buildings and outdoor areas. 

- But these spaces do not have any problem in hosting a wireless LAN.  

- Wireless Network adapters are being built into almost all the laptops by the manufacturers.

- A basic level of service is provided at which different brands concerning and client network interfaces access points that are competing with each other can inter-operate. 

- The products that have been certified by Wi-Fi alliance show back word compatibility. 

- A standard device for WiFi will work at any place in the whole world unlike our phones. 

- The WPA2 or the WiFi protected access encryption is secure provided a condition that the pass phrase used is quite strong.  

- The new protocols use for WMM i.e., Quality of service increase the suitability of the Wi-Fi regarding its use in latency - sensitive applications. 

- WMM is a power saving mechanism that is used for extending the life of the battery. 

Limitations of WiFi

- Inconsistency of the operation and spectrum assignments poses a problem worldwide.  

- The range all the WiFi networks is limited. 

- A wireless access point typically uses a stock antenna having a range of 100 m outdoors and 25m indoors.

- The frequency band is a major factor for producing variations in the range.  

- The range of Wi-Fi with a 2.4 ghz frequency block is better when compared with the 5.0 ghz frequency block Wi-Fi. 

- Some wireless routers come with detachable antennas. 

- These antennas can be removed for improving the range. 

- In their place upgraded antennas can be fitted. 

- The benefit of these antennas is that they have high directional gain at the remote devices. 

- The local regulations limit the maximum amount of power that can be transmitted by a Wi-Fi. 

- The power consumption of Wi-Fi is quite higher than the other standards.  

- This is so because of the reach requirements of the wireless LAN applications.

- There are technologies available that provide a propagation range that is much shorter. 

- One such technology is Bluetooth and has very low power consumption.  

- Other technologies such as zigbee have low power consumption, a long range but provides low data rate. 

- The most commonly used wireless encryption standard is WEP or wired equivalent privacy. 

- Even this standard has been proven to be breakable even if correct configuration is used. 

- This problem was addressed by WPA or Wi-Fi protected access standard to some extent. 

- By default the wireless access points use the encryption free mode. 

- The wireless security is disabled because of which the LAN can be openly accessed. 

What are uses of Wifi?

- Routers sometimes act as a Wi-Fi access point incorporating a cable modem or a DSL modem.

- These routers are installed in buildings and homes for providing Internet access and other inter networking services to the devices that in turn are connected to a either through a cable or wireless. 

- Similarly, there are routers that are powered by battery and they consist of a Wi-Fi access point and a mobile Internet radio modem. 

- Today smartphones come with this as a built-in capability.  

- However, this feature is disabled by the carriers. 

- The carriers might charge extra money for this. 

- The standalone facilities are provided by Internet packs. 

- The places where there is no network access, wifi is used. 

- Using Wi-Fi, a direct communication link between two computers can be established.  

- There is no intermediate point.  

- This type of transmission is termed as ad hoc wifi transmission. 

- This network mode is now very popular with the multi-player game consoles. Examples are:

       > Nintendo DS

       > PlayStation portable

       > Digital cameras

       > Other consumer electronic devices.

- A citywide Wi-Fi plan has been implemented by a number of the cities around the world.  

- In India, the first city to do so was Mysore.  

- The first city in the world was Jerusalem.

- The first city in United States was Sunnyvale in California to offer city-wide wifi. 

- Another type of wifi implementation is campus-wide wifi.  

- A number of colleges in United States have set up this kind of wifi network.  

- The first university to have it was Carnegie Mellon University. 

- Using wifi, the local area Network can be deployed in very less cost.  

- There are places where it is not possible for the physical transmission medium such as cables to reach. 

- In such places wifi network is of crucial importance.  

- Also, wifi can be easily deployed in historical buildings and outdoor areas.  

- Now, because of the increasing popularity of the Wi-Fi, the manufacturers are developing Wireless Network adapters for most of the notebooks and laptops.  

- This eventually led to a fall in the price of the Wi-Fi chip set. 

- Today, the Wi-Fi chip set is economically feasible and is included in most of the devices.  

- There are many brands of client network interfaces and access-points that are competing with each other.  

- These interfaces are able to inter-operate at a basic level. 

- The Wi-Fi certification for the products is issued by wifi alliance. 

- This makes them backwards compatible with each other. 

- A standard Wi-Fi Device is supposed to work anywhere in the world. 

- The encryption standard that is considered secure is the WPA2 or wifi protected access.  

- But, this would work only if the pass phrase that is being used is strong enough. 

- The Wi-Fi has been made more suitable with the use of new protocols such as quality of service.  

- This has made wifi compatible with latency sensitive applications.  

- Nowadays, for extending battery life power saving mechanisms such as WMM are being used.  

- These are the major uses of wifi technology.

- The usage wifi has been limited because of its limited range. 

- Therefore, in order to cover up a large area several intermediate Wi-Fi access-points have to be set up. 

- The variations in the range can be produced by varying the frequency band.  

- Wifi with a small frequency block works better than wifi with a larger frequency block.

- Wifi with the larger frequency blocks are optionally used. 

- The power of wifi network can be harnessed by using high gain direction antennas instead of using detachable antennas.  

- Another factor limiting the performance of wifi transmission is the local regulations. 

- Wifi also requires high power to operate upon. 

- This is a cause of concern for the devices' batteries.

What is Wifi technology? How does it work?

- Wifi has emerged as a very popular technology. 

- This technology has enabled the electronic devices to exchange information between them and to share the internet connection without using any cables or wires. 

- It is a wireless technology. 

- This technology works with the help of the radio waves. 

- The Wifi is defined as a WLAN (wireless local area network) product by the wifi alliance that is based on the standards defined by IEEE (802.11 standards). 

- Most of the WLANs are based upon these standards only and so this technology has been named as wifi which is the synonymous with the term WLAN. 

- The wifi-certified trademark might be used by only those wifi products which have the complete certification for the wifi alliance inter-operability. 

- A number of devices now use wifi such as the PCs, smart phones, video game consoles, digital cameras, digital audio players, tablet computers and so on. 

- All these devices can connect to the network and access internet by means of a wireless network access point. 

- Such an access point is more commonly known as a ‘hotspot’. 

- The range of an access point is up to 20 m. 

- But it has a much greater range outside.  

- An access point can be installed in a single room or in an area of many square miles. 

- This can be achieved by using a number of overlapping access points. 

- However, the security of the wifi is less compared to the wired connections for example Internet.

- This is so because a physical connection is not required by an intruder. 

- The web pages using SSL have security but the intruders can easily access the non-encrypted files on the internet. 

- It is because of this, that the various encryption technologies have been adopted by the wifi. 

- The earlier WEP encryption was weak and so was easy to break.

- Later, came the higher quality protocols such as the WPA2 and WPA. 

- The WPS or the wifi protected set up was an optional feature that was added in the year of 2007. 

- This option a very serious flaw which is that it allowed the recovery of the password of the router by an attacker.

- The certification and the test plan has been updated by the wifi alliance for ensuring that there is resistance against attacks in all the devices that have been newly certified.

- For connecting to a wifi LAN, a wireless network interface controller has to be incorporated in to the computer system.

- This combination of the interface controller and the computer is often called as the station. 

- The same radio frequency communication channel is shared by all the stations.

- Also, all the stations receive any transmission on this channel. 

- Also, the user is not informed of the fact that the data was delivered to the recipient and so is termed as the ‘best–effort delivery mechanism’. 

- For transmitting the data packets, a carrier wave is used. 

- These data packets are commonly known as the ‘Ethernet frames’. 

- Each station regularly tunes in to the radio frequency channel for picking up the transmissions that are available. 

- A device that is wifi enabled can connect to the network if it lies in the range of the wireless network. 

- One condition is that the network should have been configured for permitting such a connection. 

- For providing coverage in a large area multiple hotspots are required. 

- For example, wireless mesh networks in London. 

- Through wifi, services can be provided in independent businesses, private homes, public spaces, high street chains and so on. 

- These hotspots have been set up either commercially or free of charge. 

- Free hotspots are provided at hotels, restaurants and airports. 

What are the differences between bridges and repeaters?

Bridges and repeaters are both important devices in the field of telecommunications and computer networking. In this article we discuss about these two and differences between them. 

- The repeaters are deployed at the physical layer whereas one can find bridges at the MAC layer. 

- Thus, we called repeaters as the physical layer device. 

- Similarly, bridge is known as the MAC layer device. 

- Bridge is responsible for storing as well forwarding the data packets in an Ethernet.

- Firstly, it examines the header of the data frame, selects few of them and then forwards them to the destination address mentioned in the frame. 

- Bridge uses the CSMA/CD for accessing a segment whenever the data frame has to be forwarded to it.

- Another characteristic of a bridge is that its operation is transparent. 

- This means that the hosts in the network do not know that the bridge is also present in the network. 

- Bridges learn themselves; they do not have to be configured again and again. 

- They can be simply plugged in to the network. 

- Installing a bridge causes formation of LAN segments by breaking a LAN. 

- Packets are filtered with the help of bridges. 

- The frames that belong to one LAN segment are not sent to the other segments. 

- This implies separate collision domains are formed. 

The bridge maintains a bridge table consisting of the following entries:

1. LAN address of the node
2. Bridge interface
3. Time stamp
4. Stale table entries

- Bridges themselves learn that which interface can be used for reaching which host. 

- After receiving a frame, it looks for the location of the sending node and records it.

- It keeps the collision domains isolated from one another thus, giving the maximum throughput. 

- It is capable of connecting a number of nodes and offer limitless geographical coverage. 

- Even different types of Ethernet can be connected through it. 

- Even the repeaters are plug and play devices but they do not provide any traffic isolation. 

- Repeaters are used for the purpose of regenerating the incoming signals as they get attenuated with time and distance. 

- If physical media such as the wifi, Ethernet etc. is being used, the signals can travel only for a limited distance and after that their quality starts degrading. 

- The work of the repeaters is to increase the extent of the distance over which the signals can travel till they reach their destination. 

- Repeaters also provide strength to the signals so that their integrity can be maintained. 

- Active hubs are an example of the repeaters and they are often known as the multi-port repeaters. 

- Passive hubs do not serve as repeaters. 

- Another example of the repeaters are the access points in a wifi network. 

- But it is only in repeater mode that they function as repeaters. 

- Regenerating signals using repeaters is a way of overcoming the attenuation which occurs because of the cable loss or the electromagnetic field divergence. 

- For long distances, a series of repeaters is often used. 

- Also, the unwanted noise that gets added up with the signal is removed by the repeaters. 

- The repeaters can only perceive and restore the digital signals.

- This is not possible with the analog signals. 

- Signal can be amplified with the help of amplifiers but they have a disadvantage which is that on using the amplifiers, the noise is amplified as well. 

- Digital signals are more prone to dissipation when compared to analog signals since they are completely dependent up on the presence of the voltages. 

- This is why they have to be repeated again and again using repeaters. 

What is Polling?

- Polling is often referred to as the polled operation.

- When the statuses of the external devices are actively sampled by a client program just like a synchronous activity is referred to as the polling. 

- The common use of the polling is in the input and output operations. 

- In rare cases, polling is also called as the software driven I/O or just simply as polled I/O. 

- As and when required, polling is also carried out with the busy waiting synonymous. 

- Polling is then referred to as the busy–wait polling. 

- In this case whenever it is required to carry out an input/ output operation, the system just checks the status of the device required for fulfilling this operation until it is idle. 

- When it becomes idle it is accessed by the I/O operation. 

- Such polling may also refer to a state in which the status of the device is checked again and again for accessing it if idle. 

- If the device is occupied, the system is forced to return to some other pending task. 

- In this case the CPU time is wasted less when compared to what happens in busy waiting. 

- However, this is not a better alternative to interrupt driven I/O polling. 

- In single purpose systems that are too simple, using busy-wait polling is perfectly fine if the system cannot take any action until the I/O device has been accessed. 

- But traditionally, the polling was thought to be a consequence of the operating systems and simple hardware that do not support multitasking. 

- The polling works intimately with the low level hardware usually. 

- For example, a parallel printer port can be polled for checking whether or not it is ready for printing another character. 

- This involves just the examination of a bit. 

- The bit to be examined represents the high or low voltage stage of the single wire in the cable of the printer during the time of reading. 

- The I/O instruction by which this byte is read is also responsible for transferring the voltage state directly to the eight flip flops or circuits. 

- These 8 flip flops together constitute one byte of a register of CPU. 

Polling also has a number of disadvantages. 

- One is that there is limited time for servicing the I/O devices. 

- Polling has to be done within this time period only. 

- But in some cases there are many devices to be checked which cause the polling time to exceed the given limit. 

- The host keeps on hitting the busy bit until the device becomes idle or clear. 

- When the device is idle, the state is written in to the command register and also in the data out register. 

- The command ready bit is set to 1. 

- The controller sets the busy bit once it knows that the command ready bit has been set.  

- After reading from the command register, the controller carries out the required I/O operation on the device. 

- On the other hand, if the read bit has been set to one, the controller loads the device data in to the data in register. 

- This data is further read by the host. 

- Once the whole action has been completed, the command ready bit is cleared by the controller. 

- The error bit is also cleared for showing that the operation has been completed successfully. 

- At the end the busy bit is also set.

- Polling can be seen in the terms of master slave scenario where the master sends inquiring about the working status slave devices i.e., whether they are clear or engaged.