This week, the overall grades of 4 Diversified Telecommunication Services stocks are lower, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

Inteliquent, Inc. (IQNT) is having a tough week. The company’s rating falls from a C to a D. Inteliquent, Inc. provides a range of voice, data, Ethernet and hosted services to customers based in more than 80 countries across six continents. For more information, get Portfolio Grader’s complete analysis of IQNT stock.

Iridium Communications Inc. (IRDM) slips from a C to a D this week. Iridium Communications Inc. offers mobile satellite communications services. The company also gets F’s in operating margin growth and free cash flow. For more information, get Portfolio Grader’s complete analysis of IRDM stock.

Otelco Inc. Class A (OTEL) declines this week from a D to a F. For more information, get Portfolio Grader’s complete analysis of OTEL stock.

Slipping from a D to a F rating, Alaska Communications Systems Group, Inc. (ALSK) takes a hit this week. Alaska Communications Systems Group, Inc. provides integrated communications services primarily in Alaska. The company also gets F’s in operating margin growth. For more information, get Portfolio Grader’s complete analysis of ALSK stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.