Investors interested in Wireless Non-US stocks are likely familiar with Unicom (CHU) and Ceragon Networks (CRNT). But which of these two stocks is more attractive to value investors? We'll need to take a closer look to find out.The best way to find great value stocks is to pair a strong Zacks Rank with an impressive grade in the Value category of our Style Scores system. The proven Zacks Rank puts an emphasis on earnings estimates and estimate revisions, while our Style Scores work to identify stocks with specific traits.Right now, Unicom is sporting a Zacks Rank of #2 (Buy), while Ceragon Networks has a Zacks Rank of #3 (Hold). This means that CHU's earnings estimate revision activity has been more impressive, so investors should feel comfortable with its improving analyst outlook. But this is just one factor that value investors are interested in.Value investors are also interested in a number of tried-and-true valuation metrics that help show when a company is undervalued at its current share price levels.Our Value category highlights undervalued companies by looking at a variety of key metrics, including the popular P/E ratio, as well as the P/S ratio, earnings yield, cash flow per share, and a variety of other fundamentals that have been used by value investors for years.CHU currently has a forward P/E ratio of 17.28, while CRNT has a forward P/E of 17.42. We also note that CHU has a PEG ratio of 0.33. This figure is similar to the commonly-used P/E ratio, with the PEG ratio also factoring in a company's expected earnings growth rate. CRNT currently has a PEG ratio of 1.16.Another notable valuation metric for CHU is its P/B ratio of 0.80. The P/B is a method of comparing a stock's market value to its book value, which is defined as total assets minus total liabilities. By comparison, CRNT has a P/B of 2.05.Based on these metrics and many more, CHU holds a Value grade of A, while CRNT has a Value grade of C.CHU is currently sporting an improving earnings outlook, which makes it stick out in our Zacks Rank model. And, based on the above valuation metrics, we feel that CHU is likely the superior value option right now.Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report China Unicom (Hong Kong) Ltd (CHU): Free Stock Analysis Report Ceragon Networks Ltd. (CRNT): Free Stock Analysis Report To read this article on Zacks.com click here.